Bold black and white motifs of life and death add a dramatic flair to this 17th-century crypt.

The mummified heart of a saint lives on in this church—after a brief hiatus when it was stolen.

Theme park featuring miniature replicas of European monuments.

Climb inside an iron crystal magnified 165 billion times its normal size.

Christ's blood allegedly preserved in a Belgian town.

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

The corpse bride of Portugal.

In this historic region, homes and churches are carved into ancient volcanic rock formations.

A marvel of Byzantine engineering under the streets of Istanbul.

Catacombs turned marketplace.

An unusual round church in London with a Templar past.

God's Saharan sandbox of wrath.

This 1,300 year old monastery built atop a single rock was once only accessible depending on the whims of the tide.

This eccentrically decorated palace is replete with grottoes, fountains, tunnels, and caves.

Bordered by forest on three sides and the ocean on the other, the Great Dune of Pilat is the highest sand dune in Europe.

The Cathedral of Salamanca has a number of unusual carvings but none so surprising as a modern astronaut.

An ancient Egyptian temple in the middle of Madrid, Spain.

Founded as a refugee camp, now a popular tourist spot.

Rare karst landscape eroded from a flat seabed.