The last remaining relic of San Francisco's glittering 1915 Panama Pacific Exposition.

A collection of 20th-century automata, penny arcade games, and musical contraptions.

The seawater playground of gilded-era San Francisco burned to the ground in 1966.

In all of the 29 years it was in operation, no prisoners ever escaped successfully... or so they claim.

The "lovely red Vega" of the legendary record-settling pilot.

The actual model from the original "Star Trek" series is now on display at the National Air and Space Museum.

The beloved statue at the National Academy of Sciences is oh so inviting to sit on.

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

The highest bridge in America was built for an almost unnervingly small amount of money.

Bizarre Cavern.

Curious crustaceans support an obelisk from ancient Egypt that now stands in modern-day Central Park.

Mysterious 500-year-old tapestries depict a unicorn hunt.

A semi-scholarly approach to sex.

This English-inspired Maryland garden is home to acres of opulent plant life including bushes shaped into an entire fox hunt.

The longest escalator in the Western Hemisphere takes over three minutes to ride down.

Giant acorn-shaped 19th century gazebo from which suburban Washingtonians gazed upon the original "silver" spring.

A museum dedicated to exhibiting remarkable outsider art.

The likeness of the Baltimore music icon was unveiled in time for the anniversary of his Senate hearings on music censorship.

An abandoned cemetery lies in ruins as the surrounding forest swallows it whole.

Ant sculptures march up the side of what used to be an iconic spot in punk rock lore.

This bug-eyed water wheel uses the power of the Sun to clean up Baltimore Harbor.

A hidden alley in urban Baltimore is a haven for graffiti artists.

A winding district gerrymandered into the shape of a mantis.

One of the only memorials dedicated to journalists who died in combat.