A clone of a cloned tree that was so important it allegedly had its own guards.

An overlooked oasis of quiet on the grounds of Washington's monumental basilica.

Cold War intelligence agents monitored communist embassies from an attic in a former pigeon coop.

The development and impact of electronic media showcased in a picturesque farmhouse in Maryland.

Rediscovered after a century, the father of the American Navy was reinterred in something dredged up from Davy Jones' Locker.

A total of 14 men held the title of "president" before George Washington—their historical legacies are enshrined in the lobby of a hotel.

Politicians, bureaucrats, and military officers gathered in this field near the Capitol to settle their disputes with blood.

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

The rooster who crossed the road lives on forever in Takoma Park, Maryland.

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

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

A benevolent, 16-foot-tall river dragon lives on a suburban lawn.

An unusual sculpture, an interesting history, in a strange place, for a good cause.

What looks like a simple quaint estate in rural Pennsylvania was in the 18th century home to a small monastic community.

A tribute to the beloved, kind-hearted "homeless mayor" of Silver Spring.

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

One of the largest collections of Catalan literature and cultural materials outside of Spain, created by a community of 1960s expats.

Two dozen pinball games hidden away inside a most unlikely location.

The Forest Service's surprisingly sophisticated collection of wildfire prevention art features America's most beloved bear.

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

Three abandoned missile silos are hiding in plain sight behind a suburban development in Maryland.

The shelves in the back of this thrift store are devoted to saving, not selling, retro tech.

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

Tiny observatory made big contributions to the study of the Earth's motion.