Tunnel marathon: Is this England's wackiest race?

Some of the tunnels will be unlit and runners must wear helmets

In Portsmouth athletes are limbering up for a historic UK first - a marathon held completely underground.

The race takes runners deep below Portsdown Hill into the former Royal Navy bunkers used to plot the progress of allied troops on D-Day.

It is the idea of Sussex Trail Events - known for their quirky races - inspired by Germany's Kristallmarathon, held in a disused salt mine.

They have already hosted races in some other unlikely locations, including prisons, a pier and a multi-storey car park. So is this their wackiest race so far?

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"It's up there," said Jay McCardle, who launched Sussex Trail Events in 2012 with fellow running enthusiasts Danny Cunnett and Chris Ette.

"But, because it was a one-off and it’s quite difficult to get a multi-storey car park, I think that's actually the one people talk about the most."

The now-legendary race, in 2017, involved 60 people running laps of a disused car park in their hometown of Worthing, West Sussex.

Ultra runner Mark Johnston, who has completed 248 marathons in total, is the only person to have run all of Jay, Danny and Chris's unconventional events.

Mark Johnston (second from right) ran two marathons at Dorchester Prison in one day

"They could put on a race in a phone box and I'd turn up," he said.

"You can run around the city centre every day but this is a privilege, being able to go around prisons and car parks and museums.

"It's exciting."

Mark, from Brighton, said the most surreal event was the Night at the Museum in December 2023, when entrants ran laps inside Bovington Tank Museum in Dorset.

"One minute you'd be running through the trenches in the dark with all the banging and screaming, then in the next bit they were playing Christmas music," he said.

Fellow ultra athlete Laura Watts agreed "the Tank Museum was the craziest".

Laura Watts is the only woman to run the Badwater Ultra three times

"My Garmin didn’t work in there so I had no idea how far I'd gone but it was great," she said.

"There was so much to look at, I wanted to stop and look at all the tanks."

Laura, from Bognor Regis, is the only woman to have run the infamous Badwater Ultra in Death Valley three times.

But after taking part in races across the world, she says none have been as silly or weird as running up and down Southend Pier or around a museum.

"I love that extreme bonkers side of things," she said.

"I don’t know how they come up with some of these races – it's just brilliant.

"I think Southend Pier is one of my favourites – you can see people and there’s lots to look at - it went really quickly."

Chris, Jay and Danny are always looking for quirky running venues

The Portsdown bunkers, known as UGHQ, were built beneath Fort Southwick in 1942 but now host military-themed combat games.

Runners will run 90 laps of the tunnel network, including some 20-metre sections that could require some taller entrants to stoop.

"The lights will be going different colours to add to the sensory deprivation," said Jay.

"One of the tunnels is unlit completely so they have to have cycle helmets and headtorches."

Mark said: "You are going to be laughing all the way around.

"If I wasn't 5ft 6in, it would be tricky - a couple of guys are 6ft 4in so it will be a bit different for them."

David Andrewartha won the Dorchester Prison marathon in a mankini

The most recent event at Dorchester Prison on 2 November consisted of two 26.2-mile races in the disused Victorian jail - the second of which was in the dark.

David Andrewartha from Hayle, Cornwall, won the daytime race in about four hours, 24 minutes - while wearing an orange mankini.

The route consisted of 55 laps involving hundreds of steps up and down narrow metal staircases, prompting David to rethink his training strategy.

"I live on a plantation that's got steps so I'd been hitting 200 reps of these steps for an hour-and-a-half solid every other day," he said.

One marathon was held in a multi-storey car park, which has since been demolished

Mark, who completed both the day and night races, admitted it was "hard".

"It got quite gutty by the end," he said.

The organisers have also staged a 5k in flip flops, a marathon on treadmills and another on a school 400m grass track.

They are already planning next year and have put a call out to quirky-race enthusiasts for suggestions - offering helpful examples like "a roundabout, block of flats, football pitch, runway".

Organisers provided footwear for the Flip Flop 5k World Championship in 2022

They insist any mentions of events at a Greggs or Tesco were just a joke, although it can be tricky to know where they draw the line.

Chris Ette, who now lives in Dorset, said: "We're just looking for obscure areas and fun places to run in that would be totally different for runners, give them a whole new experience.

"We've got lots of other ideas. We are always looking for new venues and always asking runners for ideas and we try to make it happen."

When asked if the trio organised any sensible races, he laughed.

"No, we don’t, actually."

Jay, Danny and Mark Johnston ran the Kristallmarathon in February