Located just behind a quiet residential neighborhood, this is ground zero for the Salem witchcraft hysteria of 1692.

Life-sized sculpture of a blue whale made of hand-recycled plastic trash.

At the right time of day, sunlight floods through the roof of this cave and illuminates the small pavilion hidden within.

An acoustic anomaly with a mysterious cause.

This natural French spring has been turned into a magical grotto by Roman and medieval constructions.

The sinister ruins of one of the worst dam failures of the 20th century lie in this astonishing alpine setting.

Yale University's home for rare works, including the mysterious Voynich Manuscript.

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

This stone incorrectly marks the 35th parallel, causing some territorial kerfuffles.

The small cliffside monastery known as the Tiger's Nest is said to be the meditation site of an 8th-century Buddhist master.

An abandoned colonial French prison notorious for its hellish conditions.

Rusting away on the edge of New Jersey are the remains of a Cold War missile launch site.

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

This mansion turned restaurant was once a pitstop for Al Capone during his travels.

Follow the steps, and this roadside artwork will teach you how to dance.

This park contains one of the largest concentrations of cedar glades, a unique and rare ecosystem.

This large cave is a summer home to thousands of bats and has a rich history dating back to prehistoric times.

One of the Cemestos prefab homes built to secretly house thousands of Manhattan Project workers.

It may take some time to locate, but it's sure to warm even a heart of stone.

Victorian-era Egyptomania left its mark on this Nashville landmark.

This stone memorial pays tribute to a massive shipwreck which was sadly overshadowed by the death of John Wilkes Booth.

Hiding behind a grocery store is a spectacular cavern carved as part of an old limestone quarry.

This Tennessee museum is dedicated to a tragic railroad hero who inspired the famous ballad that bears his name.

This simple, broken column marks the final resting place of one of America's most famous explorers.