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.

This prehistoric sinkhole lured exclusively male mammoths to their death, much to the delight of science.

Just a man taking his prehistoric pet for a stroll.

The granddaddy of all tourist traps, built on ice water, jackalopes, and a giant dinosaur.

Enter the Forest of the Elves.

This bright yellow building is packed with sweet treats from all around the world, from chocolate-covered crickets to whoopie pies.

These curious caverns have been home to mushrooms, gangsters, and disco.

The famed architect designed this Minnesota gas station of the future with a lookout tower.

Half of a waterfall goes into the river while the other half seems to disappear.

This large midwestern cavern features impressive rock formations and an underground waterfall.

This popular park is home to a sea serpent sculpture that now overshadows the twisted history of its creation.

The small cave that housed Tennessee's "first citizen."

This wondrous hideaway is suspended in a bamboo forest above a sanctuary for rescued llamas and alpacas.

Secret gardens just a few miles from downtown Atlanta.

Scattered around Atlanta are little doors with big charm.

Suspended above the ground in a thicket of towering Georgia trees is a modern architectural wonder.

This massive store is home to an eccentric collection of vintage, retro, and peculiar goods.