The biggest solar telescope in the world helps reveal the secrets of our sun.

An Arizona museum with a collection of pharmaceutical oddities, including a jar of a gangster's chewed gum.

This golf ball–shaped former desert real estate office now houses a UFO museum.

In the past, Renaissance sex workers were encouraged to entice customers on this bridge.

These ancient ritual mounds are our best window into the culture of the ancient Mississippians.

Atlanta's strange assortment of concrete pillars inspires reflection in some, confusion in others.

3/4-scale model of the White House in Atlanta, Georgia.

Scattered around Atlanta are little doors with big charm.

Art Deco urban decay at this historical building.

The only known Futuro house in North Carolina sits along a stretch of desolate highway on the Outer Banks.  .

This North Carolina museum is keeping the pinball craze alive, with a little Space Invaders on the side.

A sculptor's dream castle turned fantastical ruin.

Perfume museum and library.

An ancient instrument used to measure the waters of the Nile so Egyptian farmers would know whether to expect famine or flood.

The ominously named cave is home to some remarkable ancient art.

This was once the center of the Birdman cult, and is now a World Heritage Site.

The largest stone moai on Rapa Nui.

This picturesque horseshoe weir was first built in the 1600s to prevent flooding in the town of Bath.

Created by one of England's most prolific labyrinth designers, inspired by Bath city history.

American soldiers discovered Europe's best one-liner at the end of World War II.

These 12th-century catacombs carved into a mountainside were a place of mysticism and Christian hermitages.

The amazing wonder cabinets of a very rich Austrian archbishop.

The medieval network of canals hidden underneath the city is opened to explorers each year.

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.