Frida Kahlo's childhood home, now a museum of her life and works.

The seamy, underground secrets of Portland's criminal past.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

Notorious artist squat renovated into legal studios.

The old Niles Canyon Aqueduct in the San Francisco Bay Area is a bemusing and secret trail through nature for wayward travelers.

The oldest home in Huntington Beach, the farmhouse is a monument to the region's pioneer past.

Instead of faces, these sculptures have barcodes—statements on societal dehumanization.

The oldest standing structure in downtown San Diego.

This conservation area is also home to many of the region's desert tortoises.

A Mysterious Masonic tomb in San Luis Obispo.

San Franciscans leave gifts and messages for the magical beings that live behind the tiny, mysterious door installed on a tree in Golden Gate Park.

Nestled in the heart of San Francisco’s bustling Financial District stands a unique homage to the Mayan and Beaux Arts.

The abandoned personal amusement park of the King of Pop.

Aqueducts have dramatically changed this old lake, now home to tufa towers and its very own species of tiny brine shrimp.

Left untouched since a double murder-suicide in the 1960s, Los Feliz murder mansion remains a neighborhood mystery.

This strange seaside tower got its name from a wealthy eccentric who would hide coins among its stones.

Rainbow-hued local gem in Venice.

The ghostly remains of an accidental sea.

This weird abode has inspired everything from the "House On Haunted Hil" to a robot hunter's pad.

The rocks in this arid basin leave trails of movement behind them.

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

An FDR-era tuberculosis sanatorium has stood abandoned in the suburbs of the U.S. capital for over 30 years.

The haunting "Hell House Altar" is one of the few remnants of an abandoned college that has been a magnet for local legends.

Jacksonville's highways rendered this century-old grammar school unusable.