The only National Monument ever to go missing for nearly 50 years then resurface in a dump.

The United States Capitol's former columns still stand.

Every drop of D.C. tap water flows through this old waterworks.

The oldest family-run luncheonette in New York, last renovated in 1948, still serves food and drinks the old-fashioned way.

The national park was once a plantation estate.

The institution is sitting on a goldmine of 21,000 paints, varnishes, pigments, and primers preserved for posterity.

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

A rotating cast of guys and dolls in front of a Washington, D.C. building.

About as hidden as can be, this specialty coffee shop is wedged between multi-story buildings at the end of a dark, skinny alleyway in Seoul.

A 300-year-old tea shop that brought tea to the English people, not to mention the Queen herself.

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

People escaping slavery may have hidden inside a corpse vault.

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

Go take a picture with the inventor of the daguerreotype photographic process.

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.

This sandwich shop has a century-old elevator behind a sheet of plexiglass.

One of the oldest used bookstores in the U.S. has been selling antiquarian treasures since 1825.

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

Fiji mermaids, mummified remains, and recreated cryptids are among the morbid oddities at this Maryland museum.

This unacceptably tall building was the real reason for Washington, D.C.'s skyscraper ban.

‘Bush the old fire dog died of poison July 5th, 1869. RIP.’

A historic ruin just 20 feet away from a busy highway onramp.

Enormous piles of historically significant stones, dumped by Congress in a forest, and abandoned for 60 years.

There's a crumbling old mansion inside the Smithsonian National Zoo.