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

A speakeasy takes on Chicago's drinking culture.

A lush green oasis in the middle of Chicago.

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

A pair of slides and a tree-lined stair corridor have been an urban oasis for nearly 40 years.

Olfactory delights in San Francisco's Botanical Gardens.

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

This shop for all your super spy needs hides an educational secret.

The only theatre in the world constructed specifically for sound movement.

Get lost in this haunting fairytale art walk through a man-made eucalyptus grove.

A tiny theater hidden in an alley plays a constant stream of short silent films for anyone willing to peer through the peephole.

This shop specializes in oddities and Victorian-inspired wonders.

These remote Florida islands have a history of sea turtles and sunken treasures, and one of the world's largest coastal brick fortresses.

A 140-year-old castle with underground caves hidden in San Francisco.

Bring your own cardboard to the slippery slopes of concrete hidden in a neighborhood park.

A psychedelic labyrinth on the San Francisco bay.

An artsy hidden staircase leads to breathtaking views of San Francisco.

A huge musical instrument played by the ocean.

The graves in Florida's oldest Black cemeteries are marked with shells, stones, and mementos of the deceased.

Neglected resting place of some of the city's early luminaries—and a woman encased in concrete.

A self-explanatory attraction allows fans to respectfully remember and honor a comedy legend.

Former utopian colony based on the belief that the universe exists in a hollow sphere.

A secret, rocky playground hidden amongst the plain white beaches of the Florida coast.

Given just one more year to live, Conrad Schuck built his dream house in Bartow, Florida.