This Arizona observatory is famous for investigations into Martian life, and as the place humans first spotted Pluto.

A spiritual vortex among the red rocks in Sedona.

A reproduction of earth's many biomes.

Visitors to this public park will also find the ruins of an old western fort.

A deserted hodgepodge of experimental structures designed by nearby university students.

A sculpture of a salmon swimming through a brick building.

Granting the right of way to ships over surface traffic since 1917.

The first park built over a freeway is a brutalist masterwork.

This former coal gasification plant found a curious second life as a popular public park.

A walk through the historic city center, under the streets of Seattle.

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

This church built atop a gas station promises to "equip you for the next stage in your life’s journey."

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

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

A former major munitions plant that has been converted into a sprawling art space.

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

The only place for a truly presidential dram.

America's first federal monument.

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

Parking garage where Bob Woodward met Watergate source "Deep Throat."

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

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

The ruins of this Thomas-Jefferson-designed mansion have been left to crumble since the Christmas Day they burnt down.

Edgar Allan Poe's old dorm is now a shrine to the author's legacy.