A centuries-old church stands as a testament to Boston's "father of architecture."

Known as the leaning temple, the sacred structure has somehow developed a severe nine-degree slant.

The ruins of the bathhouse used by the ill-fated last Aztec emperor still lie in Chapultepec Park.

This ancient jade mask depicting the Zapotec bat god was found in the ruins of the pyramids of Monte Alban.

A coal fire has been burning underground here since 1896.

Many people don't realize there’s a lot going on in—and below—the world’s tallest triumphal arch.

The tradition of open-air secondhand and antiquarian bookselling in Paris dates back to the Renaissance.

The ruined doorway is a portal to the building's turbulent and torturous past.

A tunnel with windows, so you don't miss out on the impressive views.

A collection of venomous snakes and reptiles for the whole family to enjoy.

The Cycladic architecture makes this Athens neighborhood feel like an island paradise hidden in the shadow of the Acropolis.

Did Inca children also slide down these smooth rocky slopes above Cusco?

One of Savannah's oldest and most haunted cemeteries, featuring graves desecrated by Sherman's Union Army.

A typical "Old South" manor, once owned by author Anne Rice, served as the setting for several of her witchcraft sagas.

The oldest operational cathedral in the U.S. has one shell of a way of projecting speakers' voices.

A prime example of New Orleans' unique architecture these early 20th century homes were built to look like steamboats.

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

The mysterious empty cupola behind the monumental arch points to an ancient prophecy of Delhi.

One of the longest water bridges in the world was built over a supposedly haunted swamp in Louisiana.

The modern birthplace of Irish freedom.

The fifth-longest natural arch in the world, and the longest outside China.

This volcano rises like a giant anthill from the plains below, with a road spiraling up to the rim.

Legend has it a commoner volunteered to be buried alive in the foundation so that the great fortress could be built.

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