France's highest manned weather station is the only one still inhabited by meteorologists.

Series of underground houses inhabited continuously for centuries.

Named after a militant urban guerilla, this famous former squat is a graffiti-covered stronghold of leftist culture.

Three bronze deer sculptures relax along the Scioto Mile.

A centuries-old complex of hand-dug stone chambers has sheltered locals in times of trouble.

A futuristic temple of light uses prisms and rainbows to create an atmosphere of peace.

One of the few surviving examples of the first lock and dam system built on the Ohio River.

Take a steam-powered ride straight out of the past on this Appalachian rail line.

One day a year it is legal to jump off of this astoundingly tall bridge that spans an Appalachian gorge.

Knoxville’s architectural icon was the symbol of the 1982 World’s Fair, even catching the googly eye of Bart Simpson.

The secret city built by the Manhattan Project.

A whimsical folk art garden full of punny pieces and a diorama containing 3,500 toys.

A collection of outdoor art by renowned muralist Robert Dafford depicts the history of a flooded city.

Dad jokes and wordplay abound in this comic fake cemetery.

An average of 33 million gallons of water pour out of the collapsed cave at the heart of this spherical spring.