Built for the 1962 World Cup, this fully functioning botanical clock is still ticking.

A whimsical European-style chateau that calls the coast of Chile home.

A crumbling hospital from the 1850s on Roosevelt Island.

The feral felines of Roosevelt Island have a small army of allies and an abandoned hospital all to themselves.

The façade of this building looks like a bingo board, but it's really a giant clock by a famed graphic designer.

Manhattan's lighthouse, erected at the insistence of the unsinkable Molly Brown.

A commemorative plaque hides a door that leads down to the New York Public Library's underground book bunker.

Commemorating the spot where the famous scientist fed his pigeons.

A room in New York City that contains 250 cubic yards of dirt.

Home of the Daffodil Festival, Castle Craig, and a ghostly hound.

A vast collection of rare books, manuscripts & extraordinary objects illustrating the history of medicine.

This park is home to a massive bird sanctuary. And maybe buried treasure!

This slender three-story building has also had several famous residents.

Spectacular secluded inlet with clear waters flanked by limestone cliffs.

See Malta’s history through the recreation of scenes of torture using life-sized mannequins in a former medieval dungeon.

People have been making salt here using traditional methods for centuries.

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

Despite the name, these small saltwater swimming pools have nothing to do with the Romans.

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

These sprawling military housing quarters from the 1960s are now defunct and hidden in plain sight on Malta’s Mediterranean coast.

Two large-scale sculptures of Adam and Eve greet visitors in the nude at the Time Warner Center in NYC.

This one-of-a-kind convent boasts a kaleidoscopic exterior of stars and double-headed eagles.

A mysterious, abandoned Chinese building in Mexico pays homage to the area's East Asian immigrants.

These azure waters were thought to lead to the Mayan Underworld.