The ancient latrines of the Greeks, in all their public glory.

Five sultans and their families rest in eternal splendor, teeming with overlooked beauty and drama.

A marvel of Byzantine engineering under the streets of Istanbul.

In this historic region, homes and churches are carved into ancient volcanic rock formations.

America's post-nuclear-attack chambers of Congress.

The site of Paul Revere's historic two lantern warning.

The marker offers a rare chance to be in four U.S. states at once, though there's some controversy over its geographic accuracy.

A massive sea stack famous for its appearance in The Goonies.

The land is home to swimming ponies and a legendary 18th-century treasure.

A motel dedicated to Southwestern nostalgia.

The highest point in Washington state is a volcano covered in glaciers.

This "second" cemetery represents New Orleans' attempt to keep cholera at bay.

100-year-old shipwreck you can walk up to at low tide.

An organ located deep within a cave, whose "pipes" are the geological features of the cave itself.

Treehouse motel and treehouse-building school.

A monument in Washington D.C. marks the spot from which all other roads were supposed to stem.

The sci-fi villain is a little-known inhabitant of the U.S. capital's largest cathedral.

Tucked away amidst some of the most famous addresses in the world is New York’s only fraction of a street.

Giant, natural amphitheaters made of delicate geological formations called "hoodoos."

Frank Lloyd Wright’s most iconic home dangles over a Pennsylvania waterfall.

Mysterious 500-year-old tapestries depict a unicorn hunt.

It’s not hard to see why the historic Peabody Conservatory of Music’s library has been described as a “cathedral of books.”

The hike through a narrow river flanked by the 2,000-foot-tall walls of Zion Canyon is one of the best in the world.

This historic "City of the Dead" lies prominently in the center of New Orleans' famous Garden District.