A cavernous three-story, 43,800-square-foot basement that was forgotten about for 60 years.

There's a 12-foot-tall replica of the Washington Monument hidden under a manhole nearby.

Enormous piles of historically significant stones, dumped by Congress in a forest, and abandoned for 60 years.

Franciscan monks created a facsimile of the Holy Land for North Americans who couldn’t afford the trip overseas.

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

The United States Capitol's former columns still stand.

A whopping 14,000 copper coins cover this miniature fighter jet.

An eccentric company offers eccentric millionaires the opportunity to have spaceflight-related experiences.

Volcanic stone sentinels stand watch at a Korean Bell Garden in Virginia.