When you want to come up for air, this Relais & Chateaux property also features a terrace, pool and restaurant.

Les Hautes Roches, 86 Quai de la Loire, Rochecorbon, France (00 33 2 47 52 88 88; www.

leshautesroches. com). Doubles start at 135 The Caves, Jamaica Definitely the world's grooviest cave hotel, The Caves belongs to Island Records founder Chris Blackwell. Brightly coloured bohemian decor, a great, all-day, food and drinks list and a chilled-out atmosphere are all part of the package.

While the guest cottages are all above ground, the hotel is built around a cavepeppered outcrop, dropping into the sea.

Cool off by swimming in and out of the caves below. Otherwise book in for a massage in the Aveda spa or grab a candlelit table at the hotel's cave restaurant for a dinner to remember.

The Caves, Lighthouse Road, Negril, Jamaica (00 800 688 76781; www. islandoutpost. com).

Cottages start at 400, all-inclusive Cappadocia Cave Suites, Turkey The rooms at this romantic hotel are dubbed 'fairy chimneys', which isn't stretching the imagination too much. So many of the buildings in this historic region are set into the rock . . . some so deep that whole cities have developed underground . . . that the landscape looks completely otherworldly. If you want to try Flintstone living for yourself, Cappadocia Cave Suites is a former hay barn, restored in the 1990s as a boutique hotel, with 18 atmospheric rooms.

Cappadocia Cave Suites, Gafferli Mah Unlu Sokak 19, Goreme, Turkey (00 90 384 271 2800;

www. cappadociacavesuites. com). Doubles start at 120, including breakfast Alexander's, Greece Set in the picturesque village of Oia on the island of Santorini, Alexander's has given the traditional cave house a modern twist.

The architecture is still Cycladic in style (white-washed walls and domed roofs), however, and the decor features a mix of antique wooden furniture. From the hotel's terrace the view spins out over sugarcube houses clinging to the rock and the sun setting over the sea.

Alexander's, Santorini, Greece (00 30 228 607 1818; www. alexandershotel. com). Cave houses start at 85, including breakfast Desert Cave Hotel, Australia Not so much a hotel as a luxurious mine shaft, the Desert Cave opened in Coober Pedy in 1988, making excellent use of the underground climate. That isn't as radical as it sounds . . . the local opal miners had been living below ground for years to escape the outback heat. Today's guests don't have to rough it, though. The hotel's 50 suites all have TV and internet and, though a little dated, were cleverly designed to reflect the landscape. If you think you might get cabin fever, the hotel also has rooms above ground.

Desert Cave Hotel, Coober Pedy, South Australia (00 61 886 725 688; www. desertcave. com. au).

Doubles start at 120, room only