A miniature rainforest is growing inside of a Midtown Manhattan office building.

A roaring, awe-inspiring double cascade of icy water flows through woodland Oregon like something out of a Tolkien novel.

The world’s oldest and biggest bookstore stocking only mystery, crime fiction, espionage, and thrillers.

Try not to get slimed in Tribeca.

It should come as no surprise that the best view of the Hollywood sign is from Batman's lair.

One man has carved a number of natural New Mexico caves into psychedelic sandstone temples.

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

For two weeks every June, fireflies in the Smoky Mountains perform an astonishing light show.

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

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

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

High on a hill overlooking Los Angeles lives a world famous, high power conical Tesla Coil.

James Turrell's total color immersion art installation, hidden on the top floor of a luxury handbag shop.

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

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

A theme park that suffered massive flooding during Katrina was abandoned, and now proves irresistible to trespassing explorers.

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

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

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

Amid the bustle and noise of the Financial District hides a secluded garden oasis above the city streets.

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

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.

World's first "penitentiary," meant to be humane, drove men insane.