Hide from the tourist hordes in these relatively unknown, and unguarded lava caves.

The only royal palace on U.S. soil has been a territorial capitol, a military headquarters, and a prison for a queen.

The American rainmaker and a burst dam.

This opulent hotel has been visited by Spider-Man, Charlie's Angels, and the Ghostbusters.

The freeway that never was.

The embalmed remains of the communist leader lie within a custom crystal coffin.

China's most famous acrobatics act.

An out-of-place slice of France, smack in the middle of Shanghai.

Ming Dynasty necropolis raided during the Cultural Revolution.

The most famous location in China was home to whole dynasties worth of imperial rulers.

In the days before house numbers, these colorful signs held clues about various buildings' purposes.

This city square is home to Amsterdam's oldest church and a statue honoring Dutch sex workers.

An ancient Egyptian temple in the middle of Madrid, Spain.

Madrid's romantically ornate crystal palace has been offering shelter to plants and art for over a century.

A rare set of strings by famed instrument maker Antonio Stradivarius is on display in the Royal Palace.

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

Furniture tries to escape an abandoned building in San Francisco.

The second building of its name to occupy this location might be the finest flatiron building in San Francisco.

Only hotel where you can legally launder money.

The giant pair of sexy legs sticking out the window of this costume store have become its main draw.

This turn of the century masterpiece has a mysterious goaty interloper.

This concrete tangle of square pipes has stood as a proud thorn in the city's side since the '70s.

A still functioning vaudeville carousel that has operated for over a century boasts a colorful menagerie and past.

The last remaining relic of San Francisco's glittering 1915 Panama Pacific Exposition.