From bench to vandalism to art, this silly prank seat was funny enough to become permanent.

A men’s restroom became a sandwich shop.

Shelves covered in dozens of coffee bean varieties fill this North End institution.

Ralph Waldo Emerson spent two years living here decades before it became a Frederick Law Olmsted-designed park.

The site of one of the strangest disasters in history—a wave of deadly molasses traveling at 35 mph.

The often-overlooked ruins of one of the first buildings designed by famous landscape architect Frederick Olmsted.

Radical Bookstore and Community Space.

The oldest Italian café in Boston, this spot also serves as a veritable museum of vintage coffee ephemera.

This upscale streetwear store is hidden behind a fake Snapple machine in the back of a deli.

A beautiful Victorian-era cemetery, complete with a miniature village.

An enormous, inside-out glass globe built in 1935.

One of the largest artillery pieces in the world sits in a Washington D.C. parking lot.

The discovery site of the "Capitalsaurus," the official dinosaur of Washington, D.C.

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

The oldest building in the District of Columbia was preserved because of a mistaken connection to George Washington.

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

The most accurate timepiece in the world.

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

Four bald cypress trees in Lafayette Square, across from the White House, mark the southern edge of a 100,000 year old cypress swamp.

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

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

The walls of the iconic dome are hollow and have a secret stairway.

During the Industrial Revolution this “Temple of Invention” was full of intricate miniature machines and gadgets.

Franciscan monks created a facsimile of the Holy Land for North Americans who couldn’t afford the trip overseas.