The greatest real estate coup of all time.

This memorial honors thousands of enslaved Africans and their descendants who died in colonial New York.

The smallest island in Manhattan is a manmade landfill dominated by a Buddhist peace arch.

Final resting place of the immigrant who brought artificial seltzer water to America.

The home of the first American-born saint is one of the only curved buildings in New York.

This translucent sculpture represents a quintessential component of New York City's skyline.

During the 19th century, you could pay for violence off a prix fixe menu on this Manhattan street.

A decommissioned military complex that's now a modern industrial park.

A self-made museum in Queens, New York continues to display the work of a sculptor known for paving his own way.

A Gothic-style abode built to accommodate the church's three resident peacocks.

Rummage through this sunken ship, but leave your scuba gear at home.

This historic address is home to the beloved ball and is an almost totally empty building among the most expensive real estate in the world.

Avoid gangster interaction while window-shopping.

Abandoned power station once home to a squatter community, now being developed into an arts center.

An uber-secure, windowless tower of doom in the center of Manhattan is an NSA spyscraper.

This ruined fort hidden at the top of Central Park can't seem to keep from losing its historical plaques.

Throughout this shopping mall are medieval ruins that were discovered during the mall's construction.

This spooky statue sits outside a famous Prague theater.

A surreal statue honoring Prague's favorite literary son.

An existential riddle in the world's largest ancient castle.

Despite attempts by local police to discourage it, Beatles-inspired graffiti has been a means for artists to air grievances for decades.

Walk through Czech history in Prague's largest graveyard.

The discovery of an old wall led to the creation of this fascinating museum about the city in the Middle Ages.

An ancient Viking runestone hidden in plain view in Stockholm's old town.