Heralded as the world's first theater, these ruins are often overlooked as they reside in the shadows of the Acropolis.

The unexpectedly beloved remnants of a controversial thermal power plant.

This no man's land slicing through the island is strewn with abandoned relics of another time.

A labyrinthine network of chambers with a storied past hides below Edinburgh's South Bridge.

Edinburgh's oldest statue hides within a parking lot behind the city's iconic cathedral.

Many Hindus make the long pilgrimage to this holy city to have their remains burned on the banks of the Ganges River.

Those with a sharp eye can find the hidden image of a German Shepherd on the memorial's Mural Wall.

This remarkable prehistoric town is full of watchtowers and houses that have withstood thousands of years.

An eerie collection of the surviving structures from a past celebration of the future.

Six ravens are kept captive (but well-fed) at the Tower of London to prevent the fall of the Crown.

A 16th-century fountain marks the site of a lost medieval cemetery once filled with mass graves.

The gorgeous entrances into the city's underbelly look more like grand halls than subway stops.

An ancient underground cultic temple where sunlight penetrates on the summer solstice.

The ancient necropolis houses the immense rock-cut tombs of four Persian kings.

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

This Roman statue is missing a limb from when the Venetians stole it from Constantinople during the Crusades.

Crumbling pyramids and temple ruins stand within the shadow of this sacred butte.

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

Long tunnels run under the ancient chariot racing circuit to the tower.

No one knows the meaning behind this giant sculpture of a nude woman with a fork riding a rooster in Havana.

A dreamy mausoleum honors Persia's most famous poet.

A spectacular rainbow of stained glass makes the "Pink Mosque" one of the most beautiful in Iran.

The largest crypt ever constructed in France was built in the 11th century on an ancient Druid sacred site.

Made famous by "Star Wars," these troglodyte homes face an uncertain future.