You can row a boat through this ancient underground reservoir.

This marvelous work of outsider architecture is built into the cliffs of an Israeli beach.

One of only three fountains created by the iconic architect Friedensreich Hundertwasser.

A modern-day cabinet of curiosities housed in a 300-year-old inn.

The highest point in Tennessee, Clingmans Dome bears witness to the ravages of one type of insect.

This chestnut box will not be opened until the country music legend's 100th birthday in 2046.

The art studio of an early 20th-century painter, hidden amid the Great Smoky Mountains.

An abandoned town is hidden in Great Smoky Mountains National Park.

This futuristic German spa allows visitors to float in a pool of salt water while zoning out to underwater techno.

Community bookshelf of 25-foot-tall book spines.

Tucked away between two 19th-century buildings, this small shop specializes in the macabre.

This humble hole-in-the-wall is home to an incredible pig ear sandwich and serious civil rights history.

The second-largest ceremonial mound in the United States is an artificial hill that is loosely shaped like a pentagon.

This two-room shotgun shack in Tupelo is the birthplace of a King.

William Faulkner kept his beloved estate wild and untamed.

A futuristic climate change study is nestled deep within this public land.

You can release a young butterfly at this beautiful indoor garden.

Just like the real 36th president of the United States, animatronic LBJ amuses visitors with jokes and stories.

A small island hides in plain sight on Austin's Lady Bird Lake.

The upstairs reading room is packed with millions of rare books, literary manuscripts, and historical treasures.

This eclectic Austin curiosity shop is home to all things strange and unusual.

A view-altering observatory at the University of Texas.

This eclectic, mosaic-clad home includes a bamboo ping-pong loft and a "Whispermaphones" intercom.

A grove of colossal man-made flowers built to collect the sun's rays.