A small, forgotten prison cemetery marked only by a wrought-iron fence and eerie depressions left in the ground.

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

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

The only place for a truly presidential dram.

The romance of early commercial flight still fills this Art Deco destination.

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

Volcanic stone sentinels stand watch at a Korean Bell Garden in Virginia.

The graveyard holding the remains of George Washington's slaves was forgotten for nearly 200 years.

This colonial tavern played host to George Washington, Thomas Jefferson, and other famous early Americans.

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

One of the steepest streets in the United States makes an intriguing challenge for cyclists.

With 3,000 bikes on display, the world's largest bicycle museum includes some famous rarities.

There aren't too many operational funiculars around, but Pittsburgh has two!

America's first public mental health facility.

Affectionately known as "Lord Bot," this historic statue has a cult social media following and rightly claims to be “the most metal inhabitant of the Wren Yard.”

A monument in Washington D.C. marks the spot from which all other roads were supposed to stem.

This Maryland farm is known for its amazing corn mazes and its 30-foot junkbots.

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

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

This isn't your average roadway—it's actually a National Park and a transportation pioneer.

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

This stately building in Alexandria, Virginia was built by Freemasons to honor one of their most famous members.

One street divides a single town that stands in two U.S. states.

The oddly shaped, steam-spewing building is now an art studio and gallery.