This ornate Victorian marketplace was the setting for Diagon Alley and the Leaky Cauldron in the Harry Potter films.

An ancient capital city that dates back 3,000 years old and harbors many surprises.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

A Spiritualist house of worship where believers communicate with the dead in the spirit world.

This robust fence in front of a historic Georgetown home is likely made from hundreds of recycled Revolutionary War firearms.

Helen Keller once broke ground on this historic center for the study of technologies to benefit the hearing impaired.

A historic estate packed with George Washington's heirlooms, and its own nuclear bunker.

The Byzantine, pre-Columbian, and medieval art at this stately mansion are some of the most under-appreciated collections in D.C.

Seemingly unremarkable items like empty sushi trays, chef hats, and freshness stickers are being preserved so future generations can look back on this beloved cultural import.

Perhaps the most scandalous statue of America's first president.

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

The monument's pointy aluminum tip has been melted down by repeated lightning strikes.

A heroic pigeon that, through a barrage of gunfire, delivered a message that saved over 100 lives in World War I.

A computer bug so primitive it was an actual insect.

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

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

The Pentagon sits on a former island that was in Virginia at low tide and D.C. at high tide.

Soldiers were buried next to Lee's house in the center of Arlington Cemetery to dissuade the general from reclaiming his property after the war.

The rogue roots are gradually consuming some of the historic marble grave markers.

The naval commander’s proudest moment in battle is memorialized in this unique tomb at Arlington Cemetery.

A mammoth pair of Civil War artillery guns abandoned out in the forest.

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

An original apothecary from 1792.

America's first federal monument.