The first bridge observation tower in the U.S. offers one of the best views of Maine.

Sculptures, jams, and the wild west collide at this folksy retreat.

This uninhabited island in Maine is home to various works of art left by visitors over the years.

A precariously balanced rock perches on the edge of a cliff created tens of thousands of years ago by glacial erosion.

These light, hollow rolls have been linked to Acadia National Park since the 1890s.

This historic, one-acre island is the only legal place to camp in the city of Richmond.

A genuine Tudor manor transported piece by piece from England.

This beautiful vintage movie palace has seen little change in form or function since the 1920s.

This labyrinthine resting place of Black American leaders has been reclaimed by nature.

Under a playground is a little-known sealed train tunnel that likely contains the bodies of workers trapped by cave-ins.

This 29-ton granite ball spins around at the slightest touch thanks to a scientific phenomenon.

Heron, whitewater rapids, and urban industrialism all add to the beauty of this concrete nature walk.

The Byzantine, pre-Columbian, and medieval art at this stately mansion are some of the most under-appreciated collections in D.C.

The country's oldest continually-operated mini golf course lies hidden in plain sight, eclipsed by one of D.C.'s most popular tourist attractions.

The winding route passes through an enclosed alleyway, two tunnels, and leads to the White House basement.

A hidden gem on the lawn of the U.S. Capitol Building designed by landscape architect Frederick Law Olmsted.

A lovely aquatic park built by a one-armed Civil War veteran who made a fortune from lotuses.

A wondrous old library overlooking the nation's capital.

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

One of the dwarven trees dates back to 1625 and survived the Hiroshima bombing.

Electronic inventions that resulted in products and systems we use every day are on display in this labor-of-love museum.

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

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

This suburban house is made of dirt, and almost sparked a revolution in home construction.