These ancient sacred grounds granted amnesty to those who managed to reach them.

This Hawaiian cattle ranch acts as a museum devoted to the island cowboys that predate the wild west.

Earth's tallest volcano is sacred to Native Hawaiians, and home to a dozen world-class observatories.

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

Longest road tunnel in the world features an air treatment plant and the illusion of daylight.

The grave of America's 11th president is not in some grand monument but instead it's hidden away on the grounds of the Tennessee Capital.

This award-winning men's bathroom was just too beautiful to not allow women to see.

The first car-centric shopping plaza in the U.S. brought a little bit of Spain to downtown Kansas City.

This abandoned prison castle has become an imposing gallery of graffiti art.

This giant green head remembers one of America's jazz giants.

The first artificial white water river course in North America cuts right through an Indiana city.

The largest land animal skull ever discovered.

The eccentric mansion of one of the most popular horror authors of modern times.

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

The Old Courthouse takes visitors on a captivating trip through St. Louis' timeline.

Less a museum than a bizarre fantasy world created by artists and engineers.

This spiny beast guards an artist's village while vying for the title of largest lobster in the world.

This lush Florida island is home to the ruins of a crooked ship breaker's tiny empire.

The only Bahá'í house of worship in North America and one of only a handful worldwide.

Only known mainland rookery of the threatened Stellar sea lion.

The world's longest known cave system.

This replica of the Greek structure is in the heart of Nashville.

An abandoned early-20th-century boomtown sits within the Calico Rock city limits.

Kentucky's anomalous peninsula projecting into the Mississippi River, site of legendary earthquakes and local feuds.