The old name for the cavern under Peveril Castle, Castleton, was beginning to sound impolite, even by the late 17th century. “The Intestinum Rectum of the Fiend”, was how the poet Charles Cotton described the entrance to the famous Derbyshire cave system in 1681, although he added that it was widely known by “a yet coarser name” - which has now been restored, as visitors will note on the path up to England’s largest natural cave entrance: Peak Cavern, says the welcome sign. Also known as The Devil’s Arse.

Owner John Harrison admits his tour guides don’t make too much of the “coarser” name to visiting schoolchildren. For the younger ones, at least, the cavern is impressive enough on its own.

“It’s amazing,” says nine-year-old Issub Ali. Eighty per cent of schools visit the Peak and Speedwell caverns primarily for the experience, says John. “Usually they’re not looking for a curriculum-based visit.”

So schools get a dramatic guide, who will show them the caves and tell them the stories and legends of the Devil’s Arse, which have been stunning visitors since the time of the Domesday Book (1086, when the name, derived from the flatulent sounds which sometimes emanate from underground rivers, was first recorded).

At the Devil’s Arse, there’s a demonstration of rope making, the primary industry of the villagers who lived in the cave mouth from the 1600s to the last days of the Derbyshire lead mining industry more than 100 years ago.

Children help the guide who shows how rope-makers would use simple machinery to wind flax into thick rope for use in the nearby lead mines.

Each school takes home a length of finished rope for the classroom.

Irene Heeley, today’s guide for the Years 3 and 4 pupils of St Hilda’s primary school, Oldham, tells the children about the living conditions in the cave village, “where the sun never shone, the rain never rained”.

Important wealthy visitors (including Lord Byron, Thomas Hobbes and possibly King Edward 1 and Mary Queen of Scots) were entertained by the rope-makers who also acted as cave guides, and Irene tells how local children were often sent up the cavern walls to sing to the visitors in the darkness.

Children hear about rock types and the formation of stalactites, and at Speedwell (which is visited by boat along the metre deep flooded tunnels of the former lead mine) they learn about local geology, lead mining techniques and conditions for the workers, some of whom were only five years old.

“We’ve covered science, history and geography, and the tours fit well into the topic on Victorian child workers we’ll be doing next year,” says Brendan Dunne, key stage 2 co-ordinator at St Hilda’s. “The children can now really visualise the conditions.”

But the main aim was to give children who rarely visit the countryside a chance to experience the world beyond Oldham. “They said it was the best place they’d ever been,” says Brendan.

Many educational visits are from inner-city schools, says John Harrison, who advises teachers to plan their trip around the village as well as the caverns. (Castleton also includes the 11th century Peveril Castle, and a visitor centre where teachers can buy study packs, primarily covering geographical topics.)

The tour of Speedwell lasts about 45 minutes, with 25 people per boat, and a boat leaving every 15 minutes, while Peak Cavern tours last a little over an hour. Emphasis on particular topics can be arranged beforehand, and a combined ticket is available for both caverns.

Eight-year-old Iqbal Hussain is still wide-eyed after ascending from the Devil’s Arse. “It’s better than a PlayStation,” he says.

Speedwell Cavern, tel: 01433 620512; www.speedwellcavern.co.uk. Devil’s Arse, tel: 01433 620285; www.peakcavern.co.uk. Prices (up to December 31): Speedwell - primary pound;2.90, secondary pound;3.70; PeakDevil’s Arse - primary pound;2.30, secondary pound;2.90. Teachers, one free for every 10 pupils at Peak, child rate at Speedwell