A 30-year-old Sycamore tree grown from a seed taken to the moon and back.

One of the largest collections of holy relics in the country.

Parking garage where Bob Woodward met Watergate source "Deep Throat."

The vast, legendary catacombs hold secrets much stranger than stacked bones.

Walk upon the mementos of the dead in this Parisian courtyard paved with medieval tombstones.

America's first federal monument.

An original apothecary from 1792.

Giftshop catering to cryptozoologists and anyone with a sense of humor.

With over 100 jam-packed rooms to explore plus elaborate tea services and events, the Mansion on O Street is a hidden treasure.

The site of the climactic scene from the classic horror film is now a historic landmark.

Bizarre Cavern.

This church in Pittsburgh is home to the largest collection of religious relics in North America.

Prison made famous by The Shawshank Redemption has been out of commission since 1990.

The permanent home of Elektro, the celebrity automaton of the 1939 World's Fair.

A castle built by an eccentric medieval enthusiast in rural Ohio.

A hidden network of subterranean passageways lies tangled beneath Indianapolis' bustling City Market.

A medical facility that has been kept frozen in time.