An ancient iron pillar in Delhi that seems to be rustproof.

An imperial fortress city that incorporated cultural elements from the entire Mughal empire, only to be abandoned the year it was finished.

This stunning 15th-century royal hill fort preserves the age of chivalry in Rajasthan.

The 953 windows undoubtedly make this the world's most beautiful screened porch.

Once an indicator of social class, the color blue has come to define this city on the edge of the Thar Desert.

Four distinctly unique gardens commemorate the POWs who lost their lives during the Sandakan Death Marches of 1945.

A collection of old steam and diesel locomotives sitting in a fenced-off garden.

History, geography, and shamanism meet in this eye-catching monument to the greatness of three empires.

People have been scribbling on this massive chunk of granite for more than 1,500 years.

The oldest Buddhist monastery in Mongolia has survived centuries of invasions, political shifts, and religious purges.

The enormous smoke hides within a little known, semi-secret exhibit inside Havana’s Morro Castle Historic Park.

A small museum in the Bay of Pigs gives the Cuban perspective on the famously failed U.S. invasion.

Once a favorite playground for the world's most illustrious guests, Hotel Nacional's secret weapons and bunkers reveal a more menacing side to its golden history.

A focal point of the Cuban government, this city square features one of the most iconic images in the country.

In terms of history and architecture, this is one of the most remarkable cemeteries in the world.

A huge, bustling local market in Panama City.

This abandoned five-star hotel is now a five-star urban exploration destination.

Bits of flat terrain surrounded by cliffs make one of the most beautiful landscapes in the Azores.

A lush oasis full of vibrant plants and striking geometric displays.

The Guardian of Tallinn.

Only a fragment of this 15th-century Dance of Death survives today.

Estonia's largest creative city is a vibrant bohemian hub located within a former industrial complex.

Disused seaplane hangar gets a second life as the jaw-dropping home of Estonia's museum of maritime history.

This Industrial Age architectural and engineering gem helps visitors and residents alike traverse Lisbon, “The City of Seven Hills.”