Iron Kiln Hole, one of the artificial entrances to Notts Pot 2. Photo: Andy Waddington CC-BY-SA-2.0

A team of cavers has achieved the feat of linking of establishing an underground route enabling potholers to descend in Cumbria and emerge in Yorkshire after passing through Lancashire.

The breakthrough on Sunday afternoon was the culmination of more than 50 years’ exploration of the potholes and caves on Leck Fell in a quest to find a route connecting Yorkshire, Lancashire and Cumbria.

A strenuous session digging though 140m of a boulder choke finally allowed the connection between Lost John’s Cave and Notts Pot 2. The crawl through what the team – Tim Allen, Geoff Yeadon and Mick Nunwick – describe as a dangerous and ‘desperately horrible’ chock in the limestone north-west of Ingleton.

The opening up now means a 102km (63-mile) route is possible.

As the team posted on the UK Caving forums:  “It is now possible to go underground in Cumbria, travel below Lancashire and emerge in Yorkshire – if you are hard.

“All those involved, from whatever era, should celebrate this fantastic achievement.”

But the cavers warn the latest section is not for the feint-hearted. Badlad, one of the team that made the breakthrough, said: “I have personally been trapped in a collapse under a boulder the size of a piano and I have pulled someone else out of a similar situation.

“Two other diggers have suffered head injuries from falling rock.

“It is never wise to kick or thrash around in such a place and everyone needs to be very considerate as to what they push or pull on.

“It is also disgustingly filthy, has a couple of quite tight bits and is energetic especially with a bag. Sorry it’s not nicer but there was no choice.

“If you are faint of heart or uncomfortable in dodgy chokes please do another trip.”

The proximity of the three county boundaries at on Leck Fell and Ireby Fell has led cavers to believe for decades it would be possible to link the three with an underground route, a feat the team proved at the weekend.