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.

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

An abandoned set from the 1980 film "Popeye," claimed and repurposed as a theme park by creative locals.

Hidden beneath a restaurant, underground tunnels tell the story of Malta’s tragic role in World War II.

Burial grounds for more than 1,000 bodies deep under the modern town of Rabat.

This spectacular dome managed to survive after being bombed in World War II, in an event known as the "Miracle of Mosta."

This 50-foot-deep sinkhole created in the 14th century is home to rare plants and fungi.

The eclectic seaside sanctuary caters to a rather fowl crowd.

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.

After 400 years of being closed to the public, this monastery's underground tunnels and secret garden are now a museum.