This bell is one of the last remnants of the lost city of Triadelphia.

Hidden within an idyllic suburban garden is a memorial dedicated to the victims of a terrifying spree of killings committed on U.S. soil.

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

A small museum along the Susquehanna River is home to a rich collection of Native American artifacts.

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

Built by the patriotic residents of Boonsboro in a single day.

The longest-covered bridge in the state of Maryland.

This historic lighthouse was well known for the large number of women who served as its keeper.

The ruins of this long-abandoned unsuccessful gold mine can still be found.

This ruined quarry once produced the distinctive red sandstone used for construction projects in Washington, D.C.

The oldest surviving one-room schoolhouse in Montgomery County, Maryland.

Built in 1815, the stabilized ruins of the grist mill and sawmill are now gated, but interpretive displays on the features and functions of the mill preserve its history.

The only public school for Black children in the region from 1895-1936.

The whole world in one water tank.

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

An eerie, decaying ghost town destined to fade into the forest.

A former pillar of the Black community in Ellicott City.

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

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

Walk through the history of American pop culture.

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

Captain John Smith thought these cliffs were amazing in 1608 but sharks thought so 20 million years before him.

An abandoned stretch of highway, deteriorating next to the operational one.

Although built to generate electricity for Marylanders, this dam has become an all-you-can-eat buffet for American bald eagles.