This ancient theater was once the home of fierce gladiatorial battles.

The world's largest reflecting pool is just two centimeters deep.

A well-preserved medieval village nested on a rocky outcrop and surrounded by a network of cliffs, natural bridges and canyons.

A natural arch carved by a river gave its name to the so-called "Cave of Forgotten Dreams."

Ancient paintings known as the "Sistine Chapel of Cave Art."

Brussels' favorite peeing boy has a sister.

Home to the Amorphophallus titanum "Corpse Flower," which is among the largest flowers in the world and also smells powerfully of rotting flesh when in bloom.

Books you don’t need in a place you can’t find.

The thousands of shades on display — some toxic, others impossibly rare — are a library of more than just color.

The oldest Italian café in Boston, this spot also serves as a veritable museum of vintage coffee ephemera.

The only structure left with direct ties to the Salem witchcraft trials of 1692.

Proto-CIA agents trained with grenades in the sand traps and fired machine guns from the fairways.

The wooded estate of the Forest Service employee responsible for D.C.’s cherry blossom trees.

This lovely tree was a thank you gift from the man known as "Public Enemy No.1."

The final resting place of the tragic king and queen of the Jazz Age is tucked away in a small Maryland graveyard.

Two dozen pinball games hidden away inside a most unlikely location.

This English-inspired Maryland garden is home to acres of opulent plant life including bushes shaped into an entire fox hunt.

New England's tallest light house stands on an island with a history of cannibalism and death.

Maine's oldest diner also happens to win acclaim for its elevated comfort food.

Site of a former hidden treehouse in New Orleans.

This city block-long devotional site, a replica of a famous site in France, is dedicated to the patron saint of grandmothers, mothers, and educators.

This 19th-century sugarcane plantation is one of the most well-preserved estates of its kind, including its original quarters for enslaved laborers.

Shop for books in the New Orleans house where William Faulkner once lived.

An otherworldly musical haven in The Big Easy.