A secretive collection featuring objects that were designed specifically for U.S. intelligence operations.

An organ located deep within a cave, whose "pipes" are the geological features of the cave itself.

The only recreation of William Shakespeare's indoor playhouse.

A sacred site for Native Americans surveyed by George Washington and owned by both King George III and Thomas Jefferson.

This amazingly preserved Gold Rush town is a historian's dream.

An obscure waterfall that looks like something out of a fantasy novel.

A prehistoric landscape hidden in the cliffs of Maha'ulepu.

A popular European tradition makes its way to the states on one of America's most famous bridges.

Mysterious stone tower featured in many alternative histories of the New World.

An arsenic-filled pool in the Grand Canyon takes on the appearance of a giant, overflowing pumpkin.

Beautiful Gothic-inspired lighthouse stands out among the run-of-the-mill striped fare on Bodies Island.

One of the largest, oldest, darkest, quietest motel rooms in the world.

Kings Cross Station pays tribute to its role in Britain's best-selling book series.

Send a postcard while vacationing with Satan.

One of the most popular megalithic sites in Ireland stands as a humbler version of Stonehenge.

The homestead of American patriot John Adams.

This ancient Irish religious site is covered in ancient carvings, many of which have barely aged.

Edgar Allan Poe's old dorm is now a shrine to the author's legacy.

This abandoned amusement park was built on a site with a dark history.

Railroad came. People came. Railroad left. Town died.