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

The whole world in one water tank.

A labor of love built by local hang-gliding enthusiasts, this ideal launch spot was outlawed by the authorities and has since been largely abandoned.

Time travel with sweets across history at this research-based candy store.

The last holdout of a pre-Civil War rebel who took the matter of slavery into his own hands.

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

The smallest covered bridge in Maryland.

Bizarre Cavern.

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

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

One of the only memorials dedicated to journalists who died in combat.

A pre-Industrial Age iron furnace and the site of a nearly-forgotten piece of Black history.

Washed out by the Johnstown Flood in 1889, the surviving portion of the original two-span bridge now resides at Fishing Creek.

This four-story steel sphere in Maryland was used to test biological weapons.

This general store is more than a century old and home to various oddities and antiques.

A monument marks the location of the first successful steamboat demonstration.

A cave on the Maryland border where civilians took refuge during the bloodiest battle of the Civil War.