Inside the unassuming cemetery chapel is a magnificent stained glass window and mosaics.

The angel of death appears to weep black tears at this grave marker.

Frank Lloyd Wright’s most iconic home dangles over a Pennsylvania waterfall.

This three-story Victorian mansion is now home to the National Park Service’s Historic Preservation Training Center headquarters.

An amazing example of Federal-period architecture, truly unique to this region of the state.

The whole world in one water tank.

This suburban park recalls the history of a famous tavern. Despite the name, it's no ordinary place!

Built in the 1850s, this church was of the first five churches constructed in Harper's Ferry.

The site of William McKinley's tragic assassination is only marked by an underwhelming boulder.

First planned industrial community in the United States.

The unluckiest U-boat in the entire German fleet is now on display in a Chicago museum.

A little marble compass above George Washington's (empty) tomb in the Capitol marks where D.C.'s four quadrants intersect.

The walls of the iconic dome are hollow and have a secret stairway.

The elevator that makes it possible to fly American flags in bulk over the U.S. Capitol

Corn-inthian columns with a uniquely American take on neoclassical architecture.

Rumor has it the uncarved lump behind the three famous suffragists is reserved for the first woman president.

This statue of the "father of television" stands prominently in the United States Capitol.

The 5.5-mile ring of steel posts around the Capitol Building is one of the largest (and most uniform) of its kind in the world.

This groundbreaking 16th-century map is known as "America's birth certificate."

A nostalgic bibliographic gem.

One of the three perfect vellum copies of this historic book known to exist is on display in a specially-designed case.

Rumors persist that a bottle of whiskey is sealed within this Demijohn-shaped adornment.

A Civil War Museum with some notable medical antiques.

True to its name, this little house presents like a dollhouse, and surprising details are revealed with a quick peek through the window.