A giant Troll lurks under one of Seattle's oldest bridges.

This abandoned subway station beneath the Waldorf-Astoria hotel is allegedly used to secretly transport presidents.

Manhattan’s Battery Park has a whimsical carousel full of spinning, glowing fish.

Try not to get slimed in Tribeca.

Dramatic river bend surrounds a natural red-rocked pedestal.

These remote Florida islands have a history of sea turtles and sunken treasures, and one of the world's largest coastal brick fortresses.

Dodge prohibitionists and slide through the telephone booth in Crif Dogs.

Remants of foundations, streets, and streetcar tracks inhabit the cliffs where a landslide occurred in 1929.

In all of the 29 years it was in operation, no prisoners ever escaped successfully... or so they claim.

An emerald-green grotto just a short trip from Austin.

The installation’s official name, “You Who Are Getting Obliterated in the Dancing Swarm of Fireflies,” says it all.

This secluded aqua waterfall in the Grand Canyon is the perfect swimming hole, and the Havasupai tribe's fiercely protected natural wonder.

Wondrous sandstone hoodoos where Native Americans collected clay for pottery, 9,000 years ago.

An immersive environment that is part haunted house, part choose-your-own-adventure, and part jungle gym.

A treasure trove of artifacts, books, and artwork from the "golden age" of exploration.

The oldest family-run luncheonette in New York, last renovated in 1948, still serves food and drinks the old-fashioned way.

An enormous, inside-out glass globe built in 1935.

An abandoned cemetery lies in ruins as the surrounding forest swallows it whole.

A collision of human error and natural geothermal pressure created this rainbow-colored geologic wonder.

On the Oregon coast there is a natural hole that seems to be draining the sea.

The neon signs from Las Vegas' past find their final resting place at this unusual graveyard.

Bring your own cardboard to the slippery slopes of concrete hidden in a neighborhood park.

Most-visited and most-photographed slot canyon in the American Southwest.

A tiny museum housed in a New York freight elevator specializes in the "overlooked, dismissed, or ignored."