I got into hiking because there were certain places I wanted to see that weren't accessible by car. Having a destination helped get me on the trail, and even now, I can keep going despite heat and exhaustion if the destination is more than just an overlook, peak, or end of a loop. Although I love the view from above, I usually want there to be something else to see when I get there (or at least along the way).
One of the easiest hikes for those that enjoy a bit of beautiful decay is in Malibu's Solstice Canyon, where the Paul R. Williams-designed "Tropical Terrace" burned down in the 1982 Corral Fire. Enough of the once-private estate remains to attract families, naturalists, and history hounds alike. You can see where the Roberts Ranch House kitchen and chimney once were, walk along the pathways, and gaze at the statues and fountains in a shady area cooled off by ocean breezes. On your way, you'll also pass a historic homestead, and past Tropical Terrace, you'll find a rare year-round waterfall. Time has not been kind to this property, and its heavy use has worn down the remains, so get to this one soon before it's too far-gone. Park in the lot or on a neighboring street, but read signs very carefully to avoid the wrath of Malibu Parking Enforcement.
Also designed by L.A.'s famous African-American architect Paul R. Williams is the grandiose gate to the notorious Murphy Ranch compound for Hitler supporters in Rustic Canyon, Pacific Palisades. This historic site has captured the imaginations of hikers and historians alike, because no one really knows what actually happened down there in the canyon. This parcel of Rustic Canyon is actually owned by the City of Los Angeles, though it's adjacent to Will Rogers State Park and Topanga State Park, which you can also venture into to make the hike more challenging. In addition to a cistern, machine shed, and graffiti-laden powerhouse, there are also some abandoned cars and an old, dilapidated farmhouse to explore. The Parks Department has fenced off a lot of the structures, and has been threatening to raze them over the last several years, so we may lose this history at some point. At least two epic staircases (one of about 500 steps) provide alternate entry to the mysterious ruins in this "upside down" hike, but climbing the stairs both down and up should be reserved for only the most ambitious hikers. Take the fire road through the gate at least in one direction.
One of the most historic sites in the Greater Los Angeles area is also one of the lesser known: the St. Francis Dam Disaster Site. A historic monument, and the site of California's second worst disaster (right behind the 1906 San Francisco earthquake and fires), the remains of William Mulholland's career-ending engineering failure are a short walk down the closed portion of San Francisquito Canyon Road, north of Santa Clarita in the Angeles National Forest. You can climb down to the pile of concrete rubble from when the last standing piece of the broken dam was dynamited, behind which a small creek has been taken over by frogs. Or climb up to the top of the western abutment and walk on top of the concrete wall built into the hillside. From above, you get a good view of where the dam once stood in 1928, and the scars left behind by the 250-foot wall of water that rushed down the canyon, taking everything with it. You can still find pieces of the broken dam that were deposited a couple of miles down by the flow of water. If you walk the entire length of the closed San Francisquito Canyon Road, you can visit LADWP's Power Plant #2 which was completely washed away by the flooding water, and then completely rebuilt. Beware of lots of rusty rebar sticking out in all directions. Keep your tetanus shot up to date.
For a bit lighter history, you can ascend Echo Mountain via the Sam Merrill Trail in Altadena to its peak. It was once known as the "White City," built by balloonist Thaddeus Lowe at the top of his incline railway. A major stopover for visitors to the eponymously-named mount and its posh Alpine Tavern, Echo Mountain was enough of a destination for visitors, with its ballroom, tennis court, resort, observatory, and "echophone" -- but all burned down. (The existing echophone is a replica.) This is an extremely popular hike with a narrow, crowded, and dusty trail, which is more manageable in some light rain. Beware of heading straight up Echo Mountain, along the path of the old incline railway, which should only be attempted by very experienced hikers extremely familiar with the trail and no fear of heights. For longer hikes, you can go beyond the White City along the Castle Canyon Trail and head to Inspiration Point or the site of the old Alpine Tavern. You can also walk along the path of the old Alpine Division of the Mt. Lowe Railway, a streetcar that rounded the harrowing curves of Mount Lowe past scenic points like Sentinel Rock, High Bridge, and the Cape of Good Hope. Each point has been marked with interpretive signage and archival photos from the Scenic Mount Lowe Railway Historical Committee, so you know what you're looking at. Park on the street at the top of Lake Avenue. No Adventure Pass needed.
The summer is a great time to hike to the site of the Dominator Shipwreck at Rocky Point near Palos Verdes. This trail should not be attempted in any precipitation, which would make the rocky shore way too slippery to be safe. There's no sandy beach here: even dry, these rocks are potential ankle-breakers, and it's rocky the whole way. You can hike to the wreck of this Greek freighter at any time of day, but you'll see the most -- and stay the driest -- at low tide. The debris field from the shipwreck, which was carrying wheat when it went off-course and ran ashore one night in 1961, is splayed out over a half mile, much of which lies underwater in the Pacific Ocean. Today the wreck attracts scuba divers, as it did when it first crashed, but all of the ship's valuables have already been looted and pilfered. An eyesore that caused a big stink (literally) for years after the crash is now an offbeat attraction for urban explorers and photographers. And there's still plenty of wildlife out there -- as evidenced by the heads of marine life poking out of the water, illegal spear-fishers, and lobster cages on the shore. By the time you get to the shipwreck site, you probably will have fatigued of walking on rocks, so take a shortcut up the "Drainpipe Trail." It's easier than it looks.
One of the most spectacular historic hikes with the biggest payoff is the hike along the East Fork trail to the Bridge to Nowhere in the San Gabriels' Sheep Mountain Wilderness Area. The Bridge to Nowhere is exactly as it sounds: no roads lead to it, and it connects nothing to nothing. But in the 1930s, this behemoth used to bridge a chasm for roads that were being built through Angeles National Forest to connect the San Gabriel Valley to Wrightwood -- until major storms washed everything out completely, except the bridge. It was cheaper to leave it there, exposed to the elements, than to demolish it, so nearly 80 years later, it still stands, now home to a private bungee jumping concessionaire. Want to jump off a bridge? You have to hike there. But the Bridge to Nowhere itself provides plenty of thrills on its own at no cost to visitors -- including pools of water deep enough to jump into in the summertime. The entire trail can be pretty wet, with several San Gabriel River crossings in water that can be up to waist-deep in a wet season. Be kind to your feet and wear very sturdy shoes, but unless you're wearing hip-waders, your boots are going to take in water and give you a squishy, sloshy gait. From the trailhead, the roundtrip hike is about 9 miles, but when the lot is full, parking down the road can add as much as three miles to the journey. Bring a change of pretty much everything to stay dry on the drive home.
There are plenty of other former Boy Scout camps, Charles Manson haunts, old movie ranches, abandoned mines, and other obscurities in and around L.A., so consider this a primer and not a comprehensive guide. Stay tuned for more deliciously derelict sites that have become hidden under the canopy of time.