The Aldie Gristmill was once the largest factory of its kind in Loudoun County.

This legendary urban waterfall creates a dazzling display of rainbows.

A unique collection of Western and Japanese-style graves.

A unique set of caves that spits waves back out into the ocean.

Hiding in plane sight.

During the solar phenomenon "Lahaina Noon" this bendy, curvy sculpture forms a perfectly circular shadow on the ground.

An ode to one of the first concerts broadcast via satellite.

Hawai'i's oldest wooden house was shipped around Cape Horn from Boston in 1820.

The only royal palace on U.S. soil has been a territorial capitol, a military headquarters, and a prison for a queen.

Once the site of the Hawaiian monarchy, this building was originally designed as a palace.

Little has changed in the way that this mill operates since the 18th-century.

An organ located deep within a cave, whose "pipes" are the geological features of the cave itself.

These buildings are a poignant reminder of the thousands of horses and mules who passed through this area of the Shenandoah Valley on their way to war.

At 207 feet, one of the world's longest continuous escalators.

A museum celebrating rare American motorcycles where everything runs—and none of it quietly.

The highest point in Tennessee, Clingmans Dome bears witness to the ravages of one type of insect.

At Washington's Dulles Airport is a satellite museum (no pun intended) with three quarters of a million square feet of aircraft history.

These unusual rooms on wheels are holdovers from the 1960s.

This lovely picnic spot featuring thunderous jet landings is an aircraft spotter’s dream.

A beautiful Gilded Age hotel in the White Mountains with surprising diplomatic history.

A serene plaza that commemorates one of the Granite State's most iconic figures.

Even Henry David Thoreau found this glacial pothole irresistible.

The largest cemetery for enslaved people in Loudoun County was almost lost to history, if not for the research of a minister.

This pun was simply waiting to come to life, and one defense contractor made it so.