Four glass boxes hover over 1,000 feet in the air to give visitors an unparalleled view of Chicago.

This lovely picnic spot featuring thunderous jet landings is an aircraft spotter’s dream.

FDR's Art Deco hospital tower was hopelessly inefficient.

Once home to seven different roller coasters, Glen Echo has undergone many transformations since its founding in 1891.

The United States Capitol's former columns still stand.

The iconic D.C. restaurant where the Cuban Missile Crisis was negotiated, now a Walgreens.

Architecture lovers won’t stop touching the National Gallery's 19.5 degree marble prow.

The bank that helped fund the Mexican-American War and the purchase of Alaska met its downfall after helping Augusto Pinochet launder money.

Washington's iconic carousel has a nice piece of Civil Rights history.

A super-sized promotional trick that is now a D.C. landmark.

Look closely and you’ll notice that the color changes a third of the way up the tower.

Before Metro, Washington had a robust streetcar network—and you see the remains of this infrastructure if you know where to look.

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

This seemingly out-of-place gas station by the Watergate hotel was once described as the most expensive gas station in the world.

A building shaped like the Army Corps of Engineers logo, because why not?

The little-known, 300-year history of the area includes former lives as a bustling tobacco port, parking lot, and industrial dump.

The oldest continuously operating fish market in the United States.

An overlooked memorial honoring the local Washington residents who died in World War I.

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

The romance of early commercial flight still fills this Art Deco destination.

A former major munitions plant that has been converted into a sprawling art space.

This colonial tavern played host to George Washington, Thomas Jefferson, and other famous early Americans.

This rare triple-jurisdiction drawbridge passes through Virginia, Maryland, and Washington, D.C.

This stately building in Alexandria, Virginia was built by Freemasons to honor one of their most famous members.