A self-built mosaic house and sculpture park.

The crypts of Capuchin friars decorated with the bones of over 4,000 friars, including an entire "crypt of pelvises."

An Austrian house of bones filled with hundreds of intricately painted skulls.

A church filled with the bones of hundreds of virgins martyrs—or so they say.

A 16th century chapel decorated with bones, skulls, and entire bodies hanging from the wall.

A 1,000-year-old church holds the bones of the Christian martyrs who died hiding inside it.

A spectacular walk on the flank of a gorge.

A once extravagant mansion, now reduced to ruin.

For more than two centuries, the canopy of this venerable tree has been a haven for songbirds and lovers.

The skulls and bones of thousands of soldiers line the walls of this small Italian chapel.

The bones of some 7,000 soldiers killed in the historic Battle of Solferino are stored here.

12th-century holy complex shares land with a natural park full of heavenly waterfalls and raptors.

Rare karst landscape eroded from a flat seabed.

These caves are home to a small church and were used to age cheese.

The “Sistine Chapel” of the Middle Ages merges 11th-century science and religion in wondrous hues.

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

Sitting on an Italian hilltop is this surreal fortress built by the mad inventor of electrohomeopathy.

Renaissance villa and gardens complete with a tormented colossus.

A 16th-century horror show built in a lovely Italian garden.

A spiritual sanctuary in a natural cave.

This pirate-broadcasting-tower-turned-restaurant played a rebellious role in the history of Dutch television.

This enchanting natural park is a magical example of a temperate rainforest in Europe.

A French valley with forests so lush it was nicknamed "the Small Amazonia of the Pyrenees."

These primitive rock paintings include a very beloved depiction of a woolly mammoth.