SANDSTONE caves near the Black Country were once home to England's last troglodytes.
Kinver Edge is a high heath and woodland escarpment on the Staffordshire-Worcestershire border.
A network of cavernous houses were carved into its three soft red sandstone rocks – Holy Austin, Nanny's and Vale's.
The rock houses were inhabited until the 1960s and are now owned by the National Trust.
The homes at Holy Austin were restored in 1993 to represent life in the rock houses in the early 1900s.
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The original home of Mr and Mrs Fletcher at the lower level was reconstructed based on photographs and memories.
There is now furniture, windows, doors and even stoves - just as they were when the houses were lived in.
Visitors were welcomed in October 1997 - but Nanny's and Vale's haven't been restored.
The earliest record of people living in the quirky rock houses was in 1777.
Joseph Heely took refuge from a storm and was given shelter by a "clean and decent family".
He described the rock houses as "warm in winter, cool in summer".
They had water from the well and later gas, but no electricity and sanitation was by earth closets.
Rooms were larger and ceilings higher than in the nearby cottages and a 1861 census lists 11 families living there.
Some rock houses were owner-occupied, but most were rented.
Entry into Kinver Edge today costs £7.50 for a full-paying adult.
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Away from Kinver Edge, a number of fascinating caves and caverns can be found throughout the UK.
Gaping Gill, Yorkshire
For anyone who might be afraid of heights or the dark or both, the idea of being lowered from almost 400ft up through a waterfall into a cave might seem like a daunting prospect.
However, others have been blown away by their trip down Gaping Gill in Yorkshire, where twice every year, visitors can be lowered into the cavern on a winch.
Painsill, Surrey
Painsill in Surrey is home to Europe's largest man made crystal grotto.
The grotto is described as a "highlight of any day out at Painshill" where "children are captivated and adults stand in awe of the incredible man-made feature".
Carnglaze Caverns, Cornwall
The Carnglaze Caverns are nestled 60m below ground.
They were originally created by a group of local miners over 300 years ago, but have since opened as a tourist attraction.
There are three separate caverns to explore, including one that has since been flooded and transformed into an underground lake.
Meanwhile, here are five cheap and free activities to do over the summer holidays.
