In the basement of the U.S. Capitol Building is a hidden storage room full of ornate floor tiles leftover from the 1850s.

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

Long-abandoned trolley tunnels just a mile away from the White House are turning into an art space.

The whole world in one water tank.

Once part of a dam servicing an early 19th century grist mill, the tucked-way falls are a tricky-to-find urban oasis.

This advertisement for talcum powder was painted on the rock face and has since defied removal.

The headquarters of the Audubon Naturalist Society is a small slice of heaven for nature lovers.

First built around 1848, this bridge was destroyed by arson, but original timbers are included in the replacement.

This methodist cemetery is slowly receding into the wilderness along a Maryland highway.

This hidden treasure provides a charming access point along the south side of Baker Park.

Remnants of a storybook amusement park hidden behind a strip mall.

The haunting "Hell House Altar" is one of the few remnants of an abandoned college that has been a magnet for local legends.

This abandoned Victorian-style house was built in 1884.

The United States Capitol's former columns still stand.

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

This beautiful stone arch bridge wasn't even expected to stand for one day, but people have been crossing it for centuries.

One of the oldest anatomical theaters in the U.S. still in use was once the site of an infamous cadaver riot.

This abandoned asylum was once a state of the art facility before devolving into one of the most deadly mental institutions in American history.

This free, take-a-book shop seems like a trick but isn't.

An astounding collection of medical specimens, including bits of President Lincoln.

A hidden alley in urban Baltimore is a haven for graffiti artists.

An intricately designed junk art house with four extravagant junk art cars hidden in the suburbs.

This English-inspired Maryland garden is home to acres of opulent plant life including bushes shaped into an entire fox hunt.

An FDR-era tuberculosis sanatorium has stood abandoned in the suburbs of the U.S. capital for over 30 years.