Welcome to old Florida, where a 1940s mermaid show is still enchanting visitors.

A sacred site for Native Americans surveyed by George Washington and owned by both King George III and Thomas Jefferson.

Tiki luxury on Nob Hill.

This unmarked and unloved Manhattan subway grate created one of the most iconic images in American cinema.

Aqueducts have dramatically changed this old lake, now home to tufa towers and its very own species of tiny brine shrimp.

Quite simply the largest tree in the world (by volume).

A collection of 20th-century automata, penny arcade games, and musical contraptions.

A legendary speakeasy bookstore returns from the brink.

Giant busts of 42 U.S. presidents are sitting in a field in Virginia.

A tunnel once abandoned now thrives with graffiti art as an off-limits makeshift gallery.

This historic "City of the Dead" lies prominently in the center of New Orleans' famous Garden District.

A huge musical sculpture and other art installations on the National Oceanic and Atmospheric Administration grounds.

The hike through a narrow river flanked by the 2,000-foot-tall walls of Zion Canyon is one of the best in the world.

A pedestrian island in the middle of world-famous Times Square emits a strange (and purposeful) humming noise.

This cemetery has graves dating back to the 17th century, including the city's oldest carved tombstone and an ominous cryptogram.

A self-built castle made by a mysterious man.

A modernist landscape of water and sci-fi concrete.

Hidden in an ordinary Midtown building is a one-room museum dedicated to the greatest escape artist.

Carved by a waterfall in a hard-to-reach rock formation, this heart-shaped rock has inspired romantics for decades.

The curiosities and wonders of pharmacy in a delightful historic building.

Take a drunken tour inside the world's largest known geode.

The second-largest cave chamber in the world was discovered in 1898 by a 16-year-old and a friend known as "Pothead."

Long-abandoned trolley tunnels just a mile away from the White House are turning into an art space.

A museum dedicated to the alleged Roswell Incident.