Min age is 17 for the Half. Min age 16 for the 10km. Min age 12 for the 5km. No min age for the Colourburst runs.

Two Tunnels Railway Races (Ultra, Marathon, Half Marathon, 10km, 5km, Colourburst)

4.6 · 26 reviews

From Relish Running races

Date Sun 17th August 2025
Time 10:00
Location Bath, Bath and North East Somerset
Price £10.80 - £81.00
Races 22 races
Distances 5km, 10km, Half Marathon, Marathon, Ultra

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Booked 14 times recently

Event summary

Get ready for an unforgettable running experience at the Two Tunnels Railway Races, taking place on Sunday, August 17, 2025, in the picturesque city of Bath, Bath and North East Somerset. Organised by Relish Running Races, this unique event offers an array of race distances, including an ultra, marathon, half marathon, 10km, 5km, and a family-friendly Colourburst race. Participants will have the incredible opportunity to run through the longest underground sections of any race in the UK, traversing the historic Devonshire and Combe Down Tunnels, which have been transformed into a beautiful shared-use path for runners, walkers, and cyclists.

With multiple race distances, there's something for everyone, making it a perfect day out for families and friends alike. The start and finish line is conveniently located at Brickfields Park, where you can relax and enjoy a picnic post-race. Plus, by participating, you’ll be supporting the vital work of Sustrans, with £1 from every runner’s entry going towards maintaining the Two Tunnels. So lace up your running shoes and join us for a day filled with fun, fitness, and community spirit!

Two Tunnels Railway Races (Ultra, Marathon, Half Marathon, 10km, 5km, Colourburst)

Sun 17th August 2025

An aerial view of a group of runners on a curved bridge surrounded by lush green trees and foliage. A narrow road with a car and some structures is visible under the bridge. In the background, there's a body of water bordered by more trees.

Aerial view of a road surrounded by lush greenery with people walking or cycling along it. The road leads into a tunnel at one end. Residential houses are visible on the top left, and gardens, possibly a cemetery, are on the right side of the image.

A woman wearing a blue tank top, colorful patterned leggings, and a race bib number 233 gives two thumbs up as she runs inside a dimly lit tunnel. Another runner is visible in the background, and bright light can be seen at the tunnel's exit.

Four runners, three men and one woman, are smiling as they jog or walk together along a dimly lit path at night. They are wearing race bibs numbered 401 and 394. The group appears to be enjoying the night run, embracing camaraderie and teamwork.

A group of seven people, including three adults and four children, stand in a grassy field, all wearing colorful, powder-splattered clothes and shirts that say "Color Run." They smile at the camera under a bright, sunny sky with houses visible in the background.

Organiser's Description

A truly special race that not only takes in many of Bath's beautiful attractions, but also has the longest underground section for each race distance in the UK!

Cutting right under the city of the Bath, the two tunnels offer a truly unique running experience. The Somerset & Dorset Railway closed in 1966 and until April 2013, the tunnels had been sealed and inaccessible. Thanks to the hard work and dedication of the Two Tunnels Group and Sustrans over a period of 7 years, the two tunnels now have a new lease of life as a shared use path. The first tunnel, the Devonshire Tunnel is 408m long and the second tunnel, Combe Down Tunnel is 1672m long. Both tunnels are well lit and well surfaced and have recently been converted into a shared use path for the enjoyment of runners, walkers and cyclists looking to make the most of the city whilst remaining on flatter ground.

With 2 different half marathons, 2 different 10kms, 5km, 2km and 500m Colourburst races there are events for all the family, and if they are not taking part, bring your friends and family to cheer you on. Our start and finish is at Brickfields Park in the middle of the city which also has a children's play ground and is a great spot to sit and enjoy a picnic after the race.

We are very happy to be supporting the ongoing work of Sustrans in maintaining the Two Tunnels by contributing £1 per runner to their charity. Looking to fund raise as part of your run, why not raise money for Sustrans? You will get a lovely free running vest and other goodies. Find our more here. In 2019 we donated £5,254 to Sustrans

Races

500m Colourburst

Provisional Start Time 09:20

£10.80

CLOSED
2 Km Colourburst

Provisional Start Time 09:20

£12.96

CLOSED
5km - Wave 1

Predicted Time Less Than 35mins, Provisional Start Time 10:40 Approx

£25.92

UK Athletics (UKA) save £2.00

CLOSED
5km - Wave 2

Open to All Abilities. Start Time 10:40 Approx

£25.92

UK Athletics (UKA) save £2.00

CLOSED
Return Ticket 10 Km Wave 1

Predicted Time Less Than 55mins. Provisional Start Time 11:10 - 11:10 Approx

£31.32

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Return Ticket 10km Wave 2

Predicted Time Less Than 60mins. Provisional Start Time 11:20 - 11:30 Approx

£31.32

UK Athletics (UKA) save £2.00

CLOSED
Return Ticket 10km Wave 3

Predicted Time Between 55-65mins. Provisional Start Time 11:40 - 11:50 Approx

£31.32

UK Athletics (UKA) save £2.00

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Return Ticket 10km Wave 4

Predicted Time Between 55-65mins. Provisional Start Time 12:00 - 12:10 Approx

£31.32

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Return Ticket 10km Wave 5

Predicted Time Between 55-65mins. Provisional Start Time 12:20 - 12:30

£31.32

UK Athletics (UKA) save £2.00

CLOSED
Return Ticket 10km Wave 6

Open to All. Provisional Start Time 12:40 - 12:50

£31.32

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Return Ticket 10km Wave 7

Predicted Time More Than 65mins. Provisional Start Time 12:30 - 13:00 Approx

£31.32

UK Athletics (UKA) save £2.00

CLOSED
City Ticket Half Marathon Wave 1

Predicted Time Less Than 2hrs, Provisional Start Time 10:50 - 11:00

£45.36

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City Ticket Marathon Half Wave 2

Predicted Time Less Than 2hrs 10mins, Provisional Start Time 11:10 - 11:20 Approx

£45.36

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City Ticket Marathon Half Wave 3

Predicted Time Less Than 2hrs 20mins. Provisional Start Time 11:30 - 11:40

£45.36

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City Ticket Marathon Half Wave 4

Open to All. Provisional Start Time 11:50 - 12:00.

£45.36

UK Athletics (UKA) save £2.00

CLOSED
City Ticket Marathon Half Wave 5

Open to All. Provisional Start Time 12:10 - 12:20 Approx

£45.36

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City Ticket Marathon Half Wave 6

Predicted Time Greater Than 2hrs 15mins. Provisional Start Time 12:30 - 12:40 Approx

£45.36

UK Athletics (UKA) save £2.00

CLOSED
Marathon Wave 1

Predicted Time Less Than 4hrs 15mins, Provisional Start Time 10:00

£59.40

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Booking for more than 1?
Marathon Wave 2

Predicted Time Less Than 4hrs 25mins. Provisional Start Time 10:10

£59.40

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Booking for more than 1?
Marathon Wave 3

Open to All, Provisional Start Time 10:20

£59.40

UK Athletics (UKA) save £2.00

CLOSED
50km Solo

All Runners, Provisional Start Time 08:30

£64.80

UK Athletics (UKA) save £2.00

CLOSED
50km Pair

Min Age 17 if Running 20km, Min Age 18 if Running 30km, Provisional Star Time 08:30

£81.00

UK Athletics (UKA) save £2.00

CLOSED

Book

500m Colourburst

Provisional Start Time 09:20

£10.80

CLOSED
2 Km Colourburst

Provisional Start Time 09:20

£12.96

CLOSED
5km - Wave 1

Predicted Time Less Than 35mins, Provisional Start Time 10:40 Approx

£25.92

UK Athletics (UKA) save £2.00

CLOSED
5km - Wave 2

Open to All Abilities. Start Time 10:40 Approx

£25.92

UK Athletics (UKA) save £2.00

CLOSED
Return Ticket 10 Km Wave 1

Predicted Time Less Than 55mins. Provisional Start Time 11:10 - 11:10 Approx

£31.32

UK Athletics (UKA) save £2.00

Booking for more than 1?
Return Ticket 10km Wave 2

Predicted Time Less Than 60mins. Provisional Start Time 11:20 - 11:30 Approx

£31.32

UK Athletics (UKA) save £2.00

CLOSED
Return Ticket 10km Wave 3

Predicted Time Between 55-65mins. Provisional Start Time 11:40 - 11:50 Approx

£31.32

UK Athletics (UKA) save £2.00

Booking for more than 1?
Return Ticket 10km Wave 4

Predicted Time Between 55-65mins. Provisional Start Time 12:00 - 12:10 Approx

£31.32

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Booking for more than 1?
Return Ticket 10km Wave 5

Predicted Time Between 55-65mins. Provisional Start Time 12:20 - 12:30

£31.32

UK Athletics (UKA) save £2.00

CLOSED
Return Ticket 10km Wave 6

Open to All. Provisional Start Time 12:40 - 12:50

£31.32

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Booking for more than 1?
Return Ticket 10km Wave 7

Predicted Time More Than 65mins. Provisional Start Time 12:30 - 13:00 Approx

£31.32

UK Athletics (UKA) save £2.00

CLOSED
City Ticket Half Marathon Wave 1

Predicted Time Less Than 2hrs, Provisional Start Time 10:50 - 11:00

£45.36

UK Athletics (UKA) save £2.00

Booking for more than 1?
City Ticket Marathon Half Wave 2

Predicted Time Less Than 2hrs 10mins, Provisional Start Time 11:10 - 11:20 Approx

£45.36

UK Athletics (UKA) save £2.00

Booking for more than 1?
City Ticket Marathon Half Wave 3

Predicted Time Less Than 2hrs 20mins. Provisional Start Time 11:30 - 11:40

£45.36

UK Athletics (UKA) save £2.00

Booking for more than 1?
City Ticket Marathon Half Wave 4

Open to All. Provisional Start Time 11:50 - 12:00.

£45.36

UK Athletics (UKA) save £2.00

CLOSED
City Ticket Marathon Half Wave 5

Open to All. Provisional Start Time 12:10 - 12:20 Approx

£45.36

UK Athletics (UKA) save £2.00

Booking for more than 1?
City Ticket Marathon Half Wave 6

Predicted Time Greater Than 2hrs 15mins. Provisional Start Time 12:30 - 12:40 Approx

£45.36

UK Athletics (UKA) save £2.00

CLOSED
Marathon Wave 1

Predicted Time Less Than 4hrs 15mins, Provisional Start Time 10:00

£59.40

UK Athletics (UKA) save £2.00

Booking for more than 1?
Marathon Wave 2

Predicted Time Less Than 4hrs 25mins. Provisional Start Time 10:10

£59.40

UK Athletics (UKA) save £2.00

Booking for more than 1?
Marathon Wave 3

Open to All, Provisional Start Time 10:20

£59.40

UK Athletics (UKA) save £2.00

CLOSED
50km Solo

All Runners, Provisional Start Time 08:30

£64.80

UK Athletics (UKA) save £2.00

CLOSED
50km Pair

Min Age 17 if Running 20km, Min Age 18 if Running 30km, Provisional Star Time 08:30

£81.00

UK Athletics (UKA) save £2.00

CLOSED

Course Details

Some distances have multiple route options, known as Tickets, across the year, some repeated on each date, others available only once a year. Click the links to find out more about the 10km and Half Marathon routes. You can enter one or more races at any time.

You can run multiple races on each day, please just make sure that the schedule would allow for this.

The 5km, 10km and 50km have been officially measured and are perfect for a fast time and hunting down a new PB

The Half and Marathon are a smidge over distance, still flat and fast, but a more scenic type of route.

Terrain: All our courses are very comprehensively marked and well marshalled so you can relax and enjoy your run. The Return Ticket Routes (5km, 10km, Half, 50km) are essentially 100% tarmac, aside from a small amount on grass at the start and finish. The Hilly Ticket Routes (10km, Half) are a mix of tarmac, woodland trail and stone paths. The City Ticket Routes (Half, Marathon) are all on a very solid surface, a mix of tarmac, canal towpath and river path.

Event Video

Reviews

4.6

26 reviews

haydn

·2 months ago

I ran the Two tunnels as my First half. It was super organised, having done the Bristol 10k earlier in the week, The support the staff and volunteers gave during the race was incredible, the refreshments and drinks at the stops were great and there was plenty of them around. Thank you for a great experience. Would have given 5/5, as it did say no headphones so I did not bring any(due to disqualification), however loads of people ran with theirs, so was a little frustrating that the message was not conveyed.

richard

·a year ago

Excellent race, well organised with lots of helpers to make sure you stay on course.Fast through the tunnels and beautiful scenery,a great experience

Xavier

·a year ago

It was a great event with friendly and encouraging marshalls. It was also well signposted and well organised with good feeding stations.

Nicola

·a year ago

I ran the marathon but before the race I received no race information and had to get everything searching on the site to get answers. The course is good just a shame about the incline towards the end which is demoralising.

Hi Nicola The full race information was on our website 10 weeks before the event, on the Event Info page on our website. An email was sent to all runners on the Monday of race week, with a few key reminders and further directing runners to the info page. Unfortunately emails sometimes get picked up by spam filters, but all the info was there in plenty of time :-)

Relish Running races

Libby

·a year ago

Lovely race, welcoming of all abilities, smiling and cheering marshals, and I loved running through the tunnels, especially on a warm June day. The route is shared with the public so you'll get a few cyclists overtaking but they were all respectful and shared the path (as did the runners).

Kevin

·a year ago

First time doing the two tunnels 10k.... very well organised and a fantastic run, definitely recommend and will be doing again

Martin

·a year ago

Well organised as ever, and it was quite a novelty to run through the two tunnels! My only slight gripe was that I had quite a long wait for the shuttle bus back to the P&R car park, but this didn't detract from a most enjoyable experience. For future entrants, I would definitely recommend wearing a headlight, as the lighting in the tunnels is quite dim.

akintayo

·a year ago

I really liked running the tunnels, very cool temperature as your doing the half marathon return so allowed me to go faster, I would bring a headlight. Need to work on how to start the race so we don't do the precarious mud slide down to the path....maybe throw down some gravel or bark? The marshals were great Enjoyed the race and got a half marathon PB

David

·a year ago

Great run, very well organised. Fairly flat for Bath, and the tunnels make the run interesting as well as breaking up the run. Big shout out to all of the volunteers who help to make it a great day.

Trina

·a year ago

Really great race! Very well organised with friendly encouraging marshals. I'm definitely looking forward to gaining the second half of my medal in the next race! If you haven't ran in March then get yourself booked on for June!! Thank you to everyone that made the race a success and well done to all who participated!

Rory

·a year ago

Nice flat course (I did the 10K) with a good atmosphere and friendly volunteers. The tunnels were really cool on a hot day, too!

Tim

·2 years ago

This was my first marathon and I'm very pleased I chose Relish running and this event. The course had a lot of variation that keeps you going taking in some beautiful areas on the edge of Bath and within. I was also lucky enough to win a prize which I wasnt expecting! I had an email to say I could choose another race as a prize. Looking forward to picking one, it won't be the last with Relish! Thanks, Tim Sutton

Harry

·2 years ago

Great route - but the path is not closed off so a little scary with some members of public on bikes going way too fast. Overall a good event and the tunnels are cool!

Jane

·2 years ago

Lovely venue, very well organised although the medal was disappointing, nothing like what was advertised. I understand the need for sustainable products but they could do some colour and better quality

Sam

·2 years ago

Excellent race, I did the return half (deceptive early hill for a flat course) and had a great time doing it. Everyone was super nice and the post-race snacks were excellent. Lots to do for the families during the event too. Best race I've ever done!

Alex

·2 years ago

Lovely race. Not too many people, well run and really enjoyed running through the tunnels

Gavin

·2 years ago

Ran the Hilly Half. Absolutely beautiful course across the Bath countryside, very well organised, and lovely supportive marshals. Couldn't have asked for more. Thanks to the organisers.

Matt

·5 years ago

Lovely scenery and great support. This is a lovely scenic route; lots of miles along the canal, some beautiful views of the viaducts and the tunnel stretches kept things interesting. The support was excellent and the Marathon ran smoothly. This had a very relaxed and friendly feel to the day. There was no on site parking and the park and ride was a bit of a faff for being so far away from the city centre, similarly, the start/finish line are a little away from the city centre making it a bit tricky for family to support. The route map could be a little clearer to help family track the route and offer support, but the route was very clear on the day itself. If the start/finish were in a more central location, or a closer park and ride was arranged, I'd definitely give this five stars - but the positives; a beautiful route, organised well, with super friendly people gets this four stars from me.

Lee

·5 years ago

10k route. I was so impressed on how well organised it was! The 10k route is nice and flat as you would imagine it would be being an old railway line. Lovely and cool through the tunnels, really impressive! If you’re at your infancy in running or you want a PB then this is ideal!! This is definitely one for my running event calendar!!

John

·5 years ago

Underground, overground..... Interesting, well-organised race through tunnels, villages and along a great stretch of towpath; brilliantly marshalled throughout; main difficulty apart from the relentlessness of waterside miles was weaving through Sunday crowds in the city centre stretches; rates high as a 'special' race.

Gemma

·5 years ago

Half marathon route. There is a cheeky bit of hill work mile 3-4 then goes flat along the canal found it difficult with lack of support on this part, very very cheeky hill at the end but was well organised

David

·5 years ago

Super well organised event. I did my first Two Tunnels event yesterday and was very impressed with the organisation. Getting there was easy, park and ride buses laid on. There were several waves for each distance and the tunnels made running a whole new experience.

Eddie

·5 years ago

Absolutely unique. One tunnel is 1KM , Other is 1 mile. you go through them and back, twice. So you spend the majority of this run underground and out of the heat and sun. Absolutely unique run and I really enjoyed it, very flat

Hannah

·5 years ago

An extravagant route. One of the best extravagant routes for a PB on a half marathon! Fantastic tunnels to cool off in whilst undergoing the route and an overall flat course; to enable a PB!

Angus

·5 years ago

So much fun.

Graham

·5 years ago

well orgnised.

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Location

Brickfields Park, The Hollow, Twerton, Bath, UK

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Two Tunnels Railway Races (Ultra, Marathon, Half Marathon, 10km, 5km, Colourburst)

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Relish Running races

Relish strive to put on the very best, family and beginner friendly events in the most beautiful and unique locations.

Two Tunnels Railway Races (Ultra, Marathon, Half Marathon, 10km, 5km, Colourburst)

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4.6

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Two Tunnels Railway Races (Ultra, Marathon, Half Marathon, 10km, 5km, Colourburst)

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Two Tunnels Railway Races (Half Marathon, 10km, 5km, Colourburst)

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