One of the coolest abandonments L.A. has to offer, the ruins of the old L.A Zoo still stand even though the facility was closed and gutted in the mid '60s. Today, the old zoo with its old stone structures and weathered cages is a popular spot for hikers or anyone curious about L.A. history.

There’s enough tragedy and controversy wrapped up in the ongoing saga of Sunken City for a movie script plus a sequel. This stretch of beach contains the ruins of ritzy homes and streets that fell from a lofty height during a massive landslide in 1929. Over the years, the so-called “Sunken City” gained a cult following when urban artists covered the ruins with graffiti. Plus, it just became a cool rite-of-passage hangout, especially because of San Pedro’s “No Trespassing” edict for the area.

In the midst of the Cold War, right here in L.A., while surfers and sunbathers lazed the day away, the government kept a vigilant eye out for Soviets. Decades later, the Mulholland Drive facility is still preserved. Visitors can climb the radar tower to capture panoramic shots of Los Angeles.

Reminiscent of the Sunken City in San Pedro and Hawaii's Pill Box ruins, the Topanga Fire Lookout sports similar graffiti stylings. Clamber up at your own risk and get pretty spectacular views of SoCal from the Santa Susana Mountains to the Santa Monica Mountains. To get here, you'll need to head to where Backbone Trail meets with Stunt Road. This lookout is located above Red Rock Canyon Park and it's about 2 miles roundtrip.

A moderate 9-mile round trip hike with river crossings leads to the mysterious "bridge to nowhere" -- so-called because the roads which once led up to it is now washed away. Technically, though, it does lead somewhere--to more hiking trails which lead down to a stream and falls.

The gold mine got its name in the late 1800s from the founder Charles Tom Vincent who was hunting big horn sheep in this area. The 4-mile hike is characterized by rocky cliffs and patches of dense foliage. As you go up higher you'll be treated to gorgeous views of the San Gabriel River Basin. You can also stop by the abandoned mine although you should take care to not lose your footing.

Built by the Tagami brothers in 1917 this was one of the most popular beach resorts of its time especially among Japanese-Americans. It's demise has a sad, long, and sordid history to it and perhaps the ruins are a reminder of how unfairly immigrants were treated at that time. Only a few fragments of the once-magnificent seaside vacationing spot remain slowly eroding under the destructive force of the Pacific Ocean.

Even though Bombay Beach is a desolate place sitting on the equally desolate and putrid Salton Sea, it's quite the attraction for novice filmmakers and writers. It's hard to believe this bleak town was once like Palm Springs - property sold at a premium and movie stars came here to relax at this inland California riviera. Taking a walk on this beach will require footwear; the whiteness you see is not sand - it's the disintegrated bones of long-dead fish.

This psychiatric institution was founded by Agnes Richards, a nurse determined to bring quality care to women. Built in the 1920s, the buildings and grounds were fashioned after a Spanish mission. Notable residents included Billie Burke who played Glinda the Good Witch in the classic "Wizard of Oz." Because it is a historic site it has been maintained. Its fate is unknown at this time but it may soon return to its former purpose as a retreat for the mentally ill.