This isn't your average roadway—it's actually a National Park and a transportation pioneer.

At 207 feet, one of the world's longest continuous escalators.

Rumor has it the hot dog stand was targeted by two Russian nuclear missiles.

Please don’t anchor your boat onto the Department of Defense’s underwater data cables.

Part of a WWII submarine is lurking outside the Washington Navy Yard parking lot.

This massive swimming pool is the high tech home to the human-powered submarine races.

FDR's Art Deco hospital tower was hopelessly inefficient.

These unusual rooms on wheels are holdovers from the 1960s.

At Washington's Dulles Airport is a satellite museum (no pun intended) with three quarters of a million square feet of aircraft history.

An unusual stroll through gentlemen's erotica demonstrates that pornography is timeless.

The oldest active church in Pennsylvania is also the second oldest Swedish Church in the United States.

America's smallest national park site is the former residence of exiled Polish national hero Thaddeus Kosciuszko.

These medicine cabinet staples are part of the museum's collection of everyday objects.

Alexander Hamilton’s creation caused quite a bit of controversy.

The oldest of only three existing statues of the great novelist stands in a city he did not care for.

The humble field where the first Major League Baseball game was played.

The world's third-largest crystal sphere has sat in the Penn Museum since 1927 with the exception of one outlandish theft.

An Irish Memorial commemorating those who perished due to potato blight.

The sounds of the world's largest fully functioning pipe organ dazzle shoppers at a Philadelphia Macy's.

This elaborate towering structure was once famed for its revolutionary height.

The oldest surviving botanic garden in the United States.

Dr Barnes' $25 billion private collection of art and arboretum.

In the early 1800s, surgery was also a show.

The origin of this mechanical boy was a mystery until he revealed his maker by writing it in perfect cursive.