The long underground cave's curiously shaped stalagmites have inspired many legends.

During the rainy season, this temple is almost entirely submerged, accessible only by boat.

At the right time of day, sunlight floods through the roof of this cave and illuminates the small pavilion hidden within.

Thailand's distressed elephants find peace at this Chiang Mai sanctuary.

A tall karst islet popularized by 007.

This museum has a most unusual location: inside a giant, three-headed elephant.

A treasure trove of pathological, forensic, parasitological, and anatomical specimens.

An enormous dragon scales the walls of this 17-story temple.

Spain's unique Mosque-Cathedral has been a place of worship for both Muslims and Christians throughout its history.

A curious carving hides on a marble column in the Mosque-Cathedral of Córdoba.

The world's second largest salt mine, said to have been discovered by Alexander the Great's horse.

The second-deepest known cave on Earth, hidden in an extremely remote mountain region.

Standing proud atop a Turkish bluff, this Ottoman palace has retained its grandeur despite being abandoned for centuries.

This ancient abandoned church in a remote part of Turkey is in danger of falling over.

The luxurious circular mansion built for a Communist leader now lies abandoned.

Unusual building appears to be haphazardly built from randomly piled bricks.

Elaborately carved to showcase the glorious wealth that the age of exploration brought to the Portuguese empire.

This once-forgotten oasis in the middle of Lisbon was first created over a century ago quite by accident.

Numerous impressive carvings are embedded in the trees lining this street in Marrakech.

An eccentric garden of sculptures crafted in India decorate an Irish green space dedicated to Alan Turing.

Former island in the Aral Sea used to be a top-secret Russian bio-weapons facility.

This church, better known for its weeping portrait of the Virgin Mary, also houses the world's oldest existing piece of taxidermy.

Striking ruins of a mansion that stood center stage in one of modern Brazil's most puzzling crimes.

This magical-looking island is notorious for the misfortunes suffered by its owners.