South Korea's largely symbolic, barely used gateway to the North.

Secret North Korean passage discovered below the world's most dangerous border.

Museum dedicated to awful artwork.

Berthed at the Charlestown Navy Yard in Boston, "Old Ironsides" is the oldest commissioned warship still afloat.

Two thousand artifacts from around the world collected by one woman who loved to travel.

Small and slightly hidden, the American Writers Museum is preserving the legacy of America's finest authors.

The unluckiest U-boat in the entire German fleet is now on display in a Chicago museum.

The twin towers in this Chicago fountain use 50 foot tall video screens to spit on people.

Four glass boxes hover over 1,000 feet in the air to give visitors an unparalleled view of Chicago.

Rows of stone statues are dressed up to mourn children that are lost before birth.

A wall of chewing gum moonlights as collective art.

A museum dedicated to the history and exploration of both popular music and science fiction.

Only hotel where you can legally launder money.

A man-made island in scenic San Francisco Bay.

Not merely a museum – but a whirring powerhouse that offers a subterranean peek into the heart and soul of cable car operations.

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

An essential stop before plundering, BYO Cutlass.

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

A nondescript building that's been functioning as a speakeasy for nearly a century and a half.

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

San Francisco's newly reopened hands-on science museum.

Tiki luxury on Nob Hill.

A walk-in working camera obscura produces 360-degree live images of the San Francisco coast.

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