This pink watchtower served as the seat of the Greek government after independence from the Turks.

Gladiators once walked this ancient, subterranean passage.

This ancient Greek place of assembly and marketplace is being revealed layer by layer below the modern Athens cityscape.

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

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

An ancient octagonal weather station named for the eight Greek gods of wind.

Legend says this sacred tree was a gift from goddess Athena.

Monasteries on rock pillars, once accessible only by frayed ropes.

The hallucinogenic center of the ancient world.

This huge clock made of flowers and simple machinery was once used a political weapon.

The world's longest known cave system.

This replica of the Greek structure is in the heart of Nashville.

The grave of America's 11th president is not in some grand monument but instead it's hidden away on the grounds of the Tennessee Capital.

This winding road of 318 curves is a must-visit for (careful) motorcycle and sports car enthusiasts.

The enormous 250-room Vanderbilt mansion conceals hidden doors and secret passageways.

Classy up your Big Mac with bow-tied servers and chandeliers at the world's fanciest McDonald's.

Scotland still bears an enormous scar of its Roman past.

An icon of the Battle of Britain is frozen in flight in a grand Victorian museum.

Old-fashioned knowledge and modern engineering create the world's only rotating boatlift.

One of Gettysburg’s least visited battlefield memorials is off the beaten path, but worth a visit.

This monument marks the beginning journey of a wounded soldier's leg that ended up almost two states away.

This church on a Tohono O'Odham reservation has stood since 1797.

This Art Deco service station has been providing tune-ups and turning heads for close to a century.

This titanic java kettle is one of the many kitschy landmarks located along America's OTHER famous highway.