In 1958, an MIT fraternity pledge laid down on this bridge and instituted a new, unique unit of measurement.

This bridge was the birthplace of a unit of measurement based on a fraternity joke.

This hotel was the site of major events in sports and radio history. It was also used as a detention center during World War II.

Two thousand artifacts from around the world collected by one woman who loved to travel.

Former home of an abolitionist couple who escaped slavery and established the most active Underground Railroad stop in Boston.

America's first federal monument.

Built in the 1970s, this curious modular home found new life as a sundae-shaped ice cream stand.

A 20-foot-tall quarter commemorates George Washington’s ties to Bedford County.

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

The only one-room schoolhouse remaining in Talbot County, Maryland.

A small ballpark on Maryland's eastern shore pays homage to its favorite son, the most fearsome home run hitter of the dead ball era.

The last remains of one of the oldest and largest oak trees in the United States calls this state park home.

The 72-foot giant escaped confinement in a large patch of mulch only to be reburied in the sandy shores of the Potomac River.

This rare triple-jurisdiction drawbridge passes through Virginia, Maryland, and Washington, D.C.

A mammoth pair of Civil War artillery guns abandoned out in the forest.

The final resting place of a physician rescued during the bombardment of Fort McHenry.

Evidence of a long-ago crush remains scratched into the glass at this historic Maryland House.

Remains of a historic fountain that was mysteriously lost in the demolition of a D.C. traffic circle.

This fort down the Potomac from Washington, D.C. was once the only defensive fort protecting the capital.

This dig site outside D.C. is known for its exceptionally high density of baby dinosaur fossils and dinosaur eggs.

A haunting exhibit in a wildlife refuge center highlights threatened species and the conservation efforts needed to save them.

A lawn full of retired spacecraft on display at one of NASA's first research labs.

A relic of FDR's brief foray into utopian urban planning.

A simple plaque remembers an act of WWI terrorism that obliterated an island and forever scarred the Statue of Liberty.