Mossdale Caverns

Mossdale Caverns is a cave system in the Yorkshire Dales of northern England, roughly 5 km north of Grassington on the eastern side of Wharfedale. The entrance sits at the foot of Mossdale Scar, about 425 m above sea level, where Mossdale Beck disappears underground. Passages run south-east beneath Grassington Moor. The system holds a sombre place in British caving: in 1967 it was the scene of the deadliest accident the sport has seen in the UK.

Where is Mossdale Caverns and how do you reach it?

The caves lie high on open moorland above Upper Wharfedale, north of Grassington and east of the village of Conistone. Access is on foot across pasture and moor with no waymarked visitor trail, so a topographic map or GPS app is useful. The ground is exposed and Dales weather can turn quickly. Water from Mossdale Beck travels through the cave and resurfaces at a distant rising near Kettlewell in Upper Wharfedale.

What kind of place is it, and what happened here?

This is not a show cave with lighting or tickets. It is an active stream cave meant for experienced cavers. Sections that carry water can fill rapidly after heavy rain, and levels respond to rainfall on the moor above.

On 24 June 1967, ten cavers entered the system. Four turned back after reaching Rough Chamber, while six continued. A sudden storm broke over the area while they were underground and floodwater filled the passages. The rescue effort lasted four days and involved more than 300 people, but all six men died. Published accounts name them as Michael Ryan, Bill Frakes, John Ogden, Colin Vickers, Geoff Boireau and Dave Adamson. The accident is still regarded as the worst in British caving history.

The coroner judged that bringing the bodies out was too dangerous, and the entrance was secured. The men remain in the cave. Around 1976 a safer entrance was opened again. Today the site is treated as a memorial, and anniversary services have been held to remember those who died.

Can you go underground?

Entering the system demands skill, equipment and experience of active, flood-prone caves. Visitors without that background should stay out. If you are interested in caving, local clubs such as Craven Pothole Club or the British Caving Association, which covers safety and organisation of caving in the UK, are the right starting points. Flooded sections belong to cave divers, such as those of the Cave Diving Group. Before any trip, check the forecast and the previous few days' rainfall.

What can you see above ground?

For walkers the draw is the setting itself: the rock face of Mossdale Scar, the vanishing stream and wide views across the moor. This is part of the Yorkshire Dales National Park, a region of limestone plateaus, drystone walls and deep valleys. Many routes around Grassington are easier and better marked than the walk to Mossdale, which makes them a good choice on a shorter visit.

When should you go?

Late spring and summer are best, with drier ground and long days. After heavy rain or snowmelt the moor is boggy and the beck runs strongly. In winter fog and snow make navigation harder. Always carry warm layers, water and a charged phone, remembering that reception on the upland is poor.

Frequently asked questions

Is Mossdale Caverns a tourist cave? No. It is an active river cave for experienced cavers, with no prepared visitor route.

What happened in 1967? In June 1967 six cavers died when a storm caused floodwater to surge through the cave. It remains the worst accident in British caving history.

Where exactly is it? About 5 km north of Grassington, below Mossdale Scar on the eastern flank of Wharfedale in the Yorkshire Dales.

Can I walk to the entrance? Yes, on foot across the moor, but there is no marked path. Bring a map and suitable footwear and check the weather. Do not enter the cave without experience and someone who knows the system.