Houses are tucked between, on, and underneath giant boulders.

Secret refuge and museum of the Duke of Florence.

"Stairs of the Turks", a chalky white cliff eroded conveniently into stairs, allowing for easy pillaging.

A lover's walk between hilltop towns, decorated with graffiti love notes.

One of the largest caves in the world open to the public.

This Italian foot path winds through the mountains via 52 individual tunnels.

A volcanic old faithful, Stromboli has been erupting continuously for the last 2000 years.

Medieval town turned hippie commune, once home to the secret foreskin of Jesus Christ.

Pilgrimage site for star-crossed lovers.

This 16th-century monastery has been turned into a surrealist architecture compound.

The middle finger of modernity.

A submerged archeological park still holds the wonders of a Roman Sodom.

Stalactites and stalagmites in a beautifully lit cave.

An Italian crevasse filled with abandoned buildings gives visitors a look at the world without humans.

Windblown rock formations in an ancient Roman quarry.

Installed in an act of one-upsmanship, the annual sundial in this church is also a symbolic victory for the Gregorian calendar.

The bomb-ravaged remains of of a colossal Neptune.

These delicate sand pyramids look like naturally occurring gothic spires.

A limestone wonderland of water and subterranean secrets.

Natural time capsule containing an alien ecosystem.

A magically clear, blue river that seems to spring from nowhere.

Explore the largest pure gypsum deposit in the world, and go dune sledding while you're at it.

Astonishing rock formations dot the Brimham Moor landscape.

The Jesus tree of Malta bears a striking resemblance to Christ on the cross.