Blue John Cavern

About the museum

Blue John is a rare ornamental variety of fluorspar, a banded mineral in shades of blue, purple, white and yellow, and Castleton in Derbyshire is the only place in the world where deposits of it are known. According to the cavern, the stone was first found by the Romans almost 2,000 years ago, and two vases of Blue John were supposedly uncovered during excavations at Pompeii as evidence that it was already prized as an ornamental material.

The Blue John Cavern lies on Mam Tor and is a series of caverns in the carboniferous limestone. Eight of the fifteen known veins of the mineral are found here. The cavern describes itself as one of the finest show caves in Britain and in western Europe. It is lit by electric light and is used to explain how caves form in limestone laid down on the floor of ancient seas, whose fossilised marine animals can still be seen.

Blue John has traditionally been mined by hand, because blasting can damage the crystal structure and spoil the colour banding of the stone. Miners recognise nodules buried in clay by their weight. Today visitors descend on a guided tour of the caverns, and the stone is also worked into jewellery that is sold in the cavern's shop and online.

Highlights

• Guided tour through a series of limestone caverns lit by electric light
• Home to 8 of the 15 known veins of Blue John stone
• Explanations of how caves form in limestone and of the mining of Blue John by hand
• Shop selling Blue John jewellery and gifts
• Setting on Mam Tor in the Peak District

Permanent exhibition

• Guided cavern tour – A guided walk through the Blue John caverns explaining the formation of the caves in limestone and the history and mining of Blue John stone.

Admission & discounts

Admission is paid at the cavern on the day and tickets are not sold online.

Accessibility

• Wheelchair accessible: not available
• Elevator: not available
• Accessible restroom: no information
• Accessible parking: no information
• Service dogs welcome: no information
• Tactile models & exhibits: no information
• Sign language tours: no information
• Easy-to-read materials: no information
• Audio description: no information

The tour includes 245 steps down into the cavern and the same back up, the longest flight having 96 steps, so it is not suitable for wheelchairs, prams or buggies. The steps can be narrow, uneven and damp, and there is a handrail. Visitors with breathing or heart problems should think carefully before visiting.

Kids & families

Great for kids & families

• Stroller-friendly: not available

Children of all ages are welcome and there is no age or height limit, but parents must judge whether the cavern suits them. Babies must be carried in a sling or rucksack-style carrier because the handrail needs a free hand, and prams and buggies cannot be taken in. Under 5s are free.

Getting there & parking

The cavern is on Mam Tor above Castleton. The what3words location is motivator.broadens.sends.

Amenities & dining

• Café
• Museum shop

The cafe serves soup, sandwiches, cakes, snacks, tea and coffee. It is open seasonally and at weekends, so visitors should phone to check. The shop sells Blue John jewellery and gifts, and there are picnic benches outside it. Dogs are welcome.

Events & venue rental

The museum hasn’t published any information on this.

Plan your visit