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

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

With over 100 jam-packed rooms to explore plus elaborate tea services and events, the Mansion on O Street is a hidden treasure.

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

Once a thriving business district, this former shopping area is now an urban ghost town in the heart of the city.

Once America's tallest structure, now a Baltimore landmark.

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

The design of this historic domed church was influenced by Thomas Jefferson and intended as a statement of religious freedom.

This bug-eyed water wheel uses the power of the Sun to clean up Baltimore Harbor.

An eerie, abandoned military base engulfed by nature and graffiti is now home to a local park.

Ship skeletons haunt Baltimore's waterways.

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

This beloved Baltimore spot features caged dolls, a giant Pez collection, and many, many mannequins.

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

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

Crammed into a Baltimore row house is an oddities shop that sells everything from skulls to dead insects.

It's not hard to see why the historic Peabody Conservatory of Music's library has been described as a "cathedral of books."

The last of Philadelphia's wood-paved streets is now a landmark of terrible engineering.

Step into a pastel time capsule where candy is truly dandy.

The oldest of only three existing statues of the great novelist stands in a city he did not care for.

One of Philadelphia's largest murals resides hidden under this bridge.

The oldest surviving presidential residence in the United States.

America's smallest national park site is the former residence of exiled Polish national hero Thaddeus Kosciuszko.

Old neon signs from the City of Brotherly Love provide a snapshot of the city’s evolution.