This memorial commemorating fallen Swiss Guards of the French Revolution has been called the saddest stone in the world.

Two stone columns flank the grand Venice square, but there were supposed to be three.

The industrial architecture honors the laborers who brought the Exposition Universelle of 1900 to life.

The prototype for all Nazi concentration camps.

New York's southernmost subway station is whimsically wavy.

The flagship building of an early national restaurant chain is a superb example of terra cotta art.

Forget Hollywood, one of the biggest stars in the world can be found in Roanoke, Virginia.

A former mental hospital founded in the 1930s by a eugenicist who advocated for the forced sterilization of patients.

Developed by focused shutterbugs, this museum exposes visitors to more than 6,000 different cameras.

A former pillar of the Black community in Ellicott City.

This retired stagecoach tavern is the oldest building in Cleveland.

A dazzling display of lights and crystals.

Marvel at this turn-of-the-century masterpiece that has been turned into a rather stately supermarket.

The only depiction of Abraham Lincoln holding a weapon, and the names of all 9,000 Cuyahoga veterans of the Civil War.

This Czar-funded, onion-domed, lavishly muraled Orthodox Church played a starring role in "The Deer Hunter."

The home made famous by the 1983 holiday classic is now a perfectly preserved shrine to the movie.

The only presidential monument to display a late POTUS's actual casket.

This spectacular public market has got meat, fish, vegetables, baked goods, and enough kielbasa for a lifetime.

These lush botanical gardens employ the most purrfect pest control force.

One of the world's oldest continually operating bookstores.

In use from 1742 to 1910, only flat headstones were allowed in this cemetery.

A swimming hole in the historic industrial quarry that supplied the marble for the Baltimore Washington Monument.

Baltimore's classic clock tower was once topped by a rotating, 20-ton medicine bottle.

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