Europe's largest natural bridge has a 19th century royal chateau built into its side.

Created as a "model concentration camp" to hide Nazi atrocities from the international community, this former camp-ghetto now holds a museum and memorial honoring the lives lost within.

Be(w)ar(e) the moat around this historic Czech castle.

A breathtakingly steep set of stairs is carved directly into the face of the sea cliffs of Bonifacio.

This prison on the Maltese island of Gozo is almost 500 years old, and they have the graffiti to prove it.

Two geological phenomena in one precarious locale: a towering stone window, and a deep blue void.

The fishing boats that moor in this small lagoon enter and leave through a tunnel to the sea.

One of Malta’s most popular beaches features a seemingly out-of-place statue of the Virgin Mary and baby Jesus.

These temples are among the oldest free-standing stone buildings in the world.

This is one of the very few intact windmills built by the Knights of St. John in the island nation of Malta.

A small cave network was discovered under a home in Xagħra, in 1924 when the owner was digging a well.

This 19th-century aqueduct provides insights into how water was supplied to Victoria on the island of Gozo before modern plumbing.

These clocks tell time in a theological sense.

Valletta’s outdoor theatre stands within the ruins of a 19th-century opera house.

Both the World War II Allied Forces and NATO have used this modern bunker underneath Malta’s capital.

This church is named for one of the most dramatic tales in the early Christian church.

The floor of this spectacular Baroque sanctuary is covered in memento mori.

The eyes and ears of this tower keep watch over Malta’s Grand Harbor.

This almost-forgotten underground dungeon housed several convicts over the years, including Caravaggio.

This Stone Age solar temple aligns with the sun on each equinox and solstice.

It appears as if a man is standing behind this giant airport clock, painting the hands in real time.

At the base of this tower, a plaque marks the original center point of the Netherlands.

This large sand dune in the Netherlands is home to wind-whipped trees with "floating" roots.

A grassy pyramid named after a French battle.