A gorgeous mural outside a beloved D.C. restaurant pays homage to famous Black Americans.

Fittingly, America's museum of architecture is itself a magnificently designed old building.

This colorful but controversial ceiling has been likened to a 21st-century Sistine Chapel.

The world's largest second-hand graces a clock surrounded by constantly changing flower beds. 

One of the longest wooden benches in the world snakes around Geneva's Treille Promenade.

Proto-CIA agents trained with grenades in the sand traps and fired machine guns from the fairways.

The span is crooked and made from two older recycled bridges.

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

Overshadowed by other, more famous Maltese catacombs, this ancient burial chamber has one of the best examples of a ritual agape table.

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

At more than 5,000 years old, these structures are among the oldest free-standing stone buildings in the world.

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

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

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

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

The oldest Roman lighthouse still in use.

A museum dedicated to exhibiting remarkable outsider art.

A bas relief commemorates the "Nuns of the Battlefield" who cared for soldiers on both sides of the conflict.

The hidden ruins of a mill that is linked to an attempt to assassinate the vice president of the United States.

FDR's Art Deco hospital tower was hopelessly inefficient.

A painfully obvious spy house sits right across the street from the Russian Embassy.

With over 100 jam-packed rooms to explore plus elaborate tea services and events, the Mansion on O Street is a hidden treasure.

This grand gothic brewery has been pumping out suds for over a hundred years.

An Albanian monument to the Communism that nearly crushed the country is now a crumbling wreck.