This ancient Hawaiian henge may have been an early star chart.

These picturesque Hawaiian falls are home to a rare species of fish that uses a special sucker to climb up cliffs.

This WWII aircraft museum presents its wrecks like taxidermy, complete with recreations of the crash sites.

This concrete residential area doubles as an open-air gallery.

This abstract sculpture is rumored to cast a hammer-and-sickle shadow once a year.

This bronze sculpture on a former squash court marks the secret origins of the Atomic Age.

An actual 1957 Cadillac De Ville, encased in 15 cubic yards of concrete.

This surprising gem is a world-class archeological museum hidden at the University of Chicago.

One of the largest pieces of scientific equipment ever carried on a NASA space shuttle sits in a Chicago alley.

At Chicago's revered Field Museum, visitors are invited to learn about and literally explore DNA.

An unusually designed bridge from the 1920s was built to withstand the tides and winds of Maine.

Stone monument honoring a town founder has a witch-boot shaped stain and a curse to go with it.

The first bridge observation tower in the U.S. offers one of the best views of Maine.

A precariously balanced rock perches on the edge of a cliff created tens of thousands of years ago by glacial erosion.

This 19th century granite fortification is one of the most well preserved forts in New England.

The world's largest rotating world.

This tiny patch of arid sand sits in one of the greenest states in the United States.

The world's only international cryptozoology museum is host to an unrivaled collection of mysterious objects.

Its unique collection details the history of the state's svelte railroads.

Every Tuesday, students let off steam by screaming into the night air.

This homeless brass fox tugs at your heartstrings from the foot of a Stockholm bridge.

An ancient Viking runestone hidden in plain view in Stockholm's old town.

The world's largest model of our planetary system.

One of the world's first dedicated bank buildings in the world is now the oldest one.