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

This grand gothic brewery has been pumping out suds for over a hundred years.

Long-abandoned trolley tunnels just a mile away from the White House are turning into an art space.

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

A wondrous old library overlooking the nation's capital.

The United States Capitol's former columns still stand.

In Chicago, a pizza-enthusiast has opened a museum dedicated to the history of pizza.

This awkward aquarium sculpture is one of the strangest statues in Chicago.

A 400-foot-tall tall map of Chicago makes this once-ignored building stand out.

An outdoor urban gallery of large-scale artworks by the world's most influential street artists.

This museum celebrating the almighty dollar lets visitors literally stand in the shadow of a million bucks.

Each of these gorgeous, intricately decorated rooms is painstakingly crafted to the scale of 1 inch: 1 foot.

Hidden on the 7th floor of a historic building, this Cajun spot features wall-to-wall bottles of hot sauce.

The iconic Chicago sculpture hides a beautiful and easily overlooked plaque on the backside.

This massive stained-glass masterpiece is thought to be the largest Tiffany dome in existence.

In the basement of the U.S. Capitol Building is a hidden storage room full of ornate floor tiles leftover from the 1850s.

From Coke II to Google Glass, this exhibit features some of the most spectacular commercial flops.

Swedish mice can dine at the Nuts of Life restaurant or take a date to the amousement park.

Wedding chapel's mysterious spiral staircase said to be miraculously constructed.