A cheeky architectural easter egg.

Beirut's thinnest building was the result of feuding brothers.

This quirky outpost and gallery inside a former church is an unexpected trove of handcrafted art.

This funicular railway rumbles along for a mile up the nearly vertical face of Chattanooga’s Lookout Mountain.

This head-spinningly bizarre Depression-era art cave is wall-to-wall quartz and Jesus.

The secret city built by the Manhattan Project.

The oldest operating Mississippi River–style steamboat still navigates the Ohio River.

Origin of the blue-skinned Fugates of eastern Kentucky.

Hidden behind Lincoln's head is a 70-foot-long chamber containing enamel plates documenting American history, sealed in a teakwood box in a titanium vault.

Site of the 1879 Cheyenne Outbreak and the site where famed Sioux chief Crazy Horse met his fate.

A small Wyoming town is home to the state's oldest-operating soda fountain.

The installation’s official name, “You Who Are Getting Obliterated in the Dancing Swarm of Fireflies,” says it all.