Relics of the 1894 Midwinter Exposition continue to delight visitors today.

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

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

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

This shop specializes in oddities and Victorian-inspired wonders.

A "gravitational anomaly" located in the redwood forests just outside of Santa Cruz, California.

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

A psychedelic labyrinth on the San Francisco bay.

A peculiar mansion built by the troubled heir to the Winchester Rifle Company fortune.

This Welsh village gave itself a ridiculous name in a publicity stunt a century ahead of its time.

A harem-inspired Moorish fantasy design in a Victorian-era Welsh castle.

The oldest house in Manhattan is now a museum that remembers the home's sordid history of scandals, vice-presidents, and ghosts.

A clock set into the concrete outside a Manhattan jeweler has been telling time underfoot for over a century.

The remnants of two World's Fairs are here, complete with a 12-story globe, a mini-Manhattan, and a UFO-shaped pavilion.

Under a glass sidewalk lie the remains of some of Manhattan's oldest buildings.

This whimsical group of statues is a favorite of children who love to climb all over Lewis Carroll's beloved characters.

The oldest operating apothecary in the US has treated everyone from Thomas Edison to Mark Twain.

Ride the subways of yesteryear.

Hidden in plain sight on a pair of Manhattan subway tunnels are a pair of public instruments that sing to each other.

An unassuming secret door once led to a legendary watering hole.

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

This cemetery has graves dating back to the 17th century, including the city's oldest carved tombstone and an ominous cryptogram.

Whisper secrets in a busy station only to be heard on the other side of this acoustic arch.

A semi-scholarly approach to sex.