Read between the lines of the subway map to find the hidden abandoned Civil War fort.

A long abandoned hospital building on the outskirts of NYC.

Beneath the mossy overgrowth covering this once-sprawling campus lies decades of history and the secrets that come with it.

A formerly abandoned mental institute, now back in business.

It should come as no surprise that the world's largest artichoke lies in the town that calls itself the "Artichoke Center of the World."

A strange house built only at night, with rumored mystic inspiration.

Once close to extinction, there is no shortage of elephant seals on the beaches of Año Nuevo State Park.

Since 1973, this block has been home to the most concentrated collection of murals in San Francisco.

This private residence was the template for one of the most beloved television homes of all time.

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

An abandoned, unfinished mansion on grounds strewn with lava rocks.

Concrete strongholds stand guard over the Golden Gate.

Discovered by cows, these upstate New York show caves are presented with a healthy dose of psychedelic folk art.

Why have you never heard of the second most popular tourist site in New York?

Soaring over the Niagara Whirlpool since 1916.

This statue inspired by Renoir's famous painting embodies the jovial spirit of Key West.

The former home of the Nobel Prize-winning American writer is now home to dozens of six-toed cats.

A monument celebrating the idea of reaching inaccessible places.

A mysterious castle built as a monument to lost love.

Scenic mount trashmore, Virginia Beach's most curious waterfront still has a couple of secrets.

A museum dedicated exclusively to aircraft used in the military.

A dramatic, 360-degree recreation of Pickett's Charge in the Civil War.

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

A pre-Industrial Age iron furnace and the site of a nearly-forgotten piece of Black history.