An odd, ancient window that may have once been part of a brutal prison is embedded in the side of New York's Police Plaza.

On the Fourth of July this area will transform into a Pompeii-like storm of falling embers and ash.

Atop this media building, two hives containing more than 30,000 bees keep the surrounding area vibrant.

There’s a special club house at the top for the bell ringers.

Legend has it that President Grant’s frequent drinking in the lobby gave rise to the term “lobbyist.”

Housing the National Women's Party since 1929, this historic house is now a monument to the fight for gender equality.

The fine fabric handwoven at Biltmore Industries was once coveted around the world.

Classy up your Big Mac with bow-tied servers and chandeliers at the world's fanciest McDonald's.

The U.S. Supreme Court's secret Cold War relocation facility in the mountains of North Carolina.

The enormous 250-room Vanderbilt mansion conceals hidden doors and secret passageways.

The fountains of the U.S. Navy Memorial are annually salted with water from the Seven Seas as part of a nautical ritual.

Coins and medals straight from the mint await visitors to this shop in the nation's capital.

Light bulbs, scrap wood, and tinfoil comprise this homemade throne of the gods.

This unassuming passageway played a key role in one of the most important events in U.S. history.

Over the last century, this elegant columned facade has been home to the headquarters of a bank, several nightclubs, and a restaurant.

This pharmacist and his patient greet visitors to the National Community Pharmacists Association.

The final resting place of an unidentified revolutionary soldier sits behind a Virginia church.

This small pedestal marks the spot of the first lot of land sold in Alexandria, Virginia in 1749.

This unique museum cafeteria showcases the history and regional diversity of African American cuisine.

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

This mysterious structure by the Washington Monument is a flood barrier designed to protect the White House against rising waters.

A tiny monument to the unsuccessful attempt by Thomas Jefferson to place the prime meridian in Washington.

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

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