Visit the Laas Geel cave art

Ancient rock-hewn town on the Silk Road, inhabited from the Iron Age.

River cave of Maya skeletons and artefacts.

Rock-cut cave temples in Maharashtra, crowned by the monolithic Kailasa temple.

Cave monastery above a river bend.

Renaissance castle built into the mouth of a cliff cave, with secret tunnels used by a robber knight.

Canyon wall stencilled with hundreds of hands up to 9,000 years old — the oldest art in South America, and a UNESCO site.

White travertine terraces and pools.

The "museum without walls": grassy royal burial mounds, the Cheomseongdae observatory and Silla-dynasty treasures across the town.