Long before Marin County became one of the wealthiest enclaves in the nation and the South Bay earned the name Silicon Valley, the Bay Area was a place rich in natural resources that attracted explorers, immigrants, and entrepreneurs.

Thanks to the abundance of parkland protected by previous generations, relics from as far back as the 16th and 17th centuries are still visible on the landscape. Lace up your hiking boots and hit these six trails for a glimpse into our region's past, from its native history to its strategic importance in the Cold War.

The hospital at Fort McDowell on Angel Island.(Courtesy of Angel Island Company)

Angel Island State Park

Angel Island State Park has no shortage of interesting historic sites but, thanks to a $40 million restoration project completed this year, you can now visit its most essential. In the early 20th century, Angel Island served as a quarantine station for immigrants, particularly those from China and Japan crossing the Pacific to San Francisco. The births, illnesses, and deaths of the one million people detained on the island between 1910 and 1940 took place at its only hospital. Explore the abandoned medical center on a hike from Ayala Cove, where boats dock from SF and Tiburon. For an easy 2.5 mile stroll, take the mostly paved path around the the island's perimeter to the hospital at Fort McDowell; after you explore, continue along the trail past historic batteries to return to Ayala Cove (5 miles roundtrip). For a more intense hike, take the North Ridge trail from the east side of Ayala Cove towards the summit of Mt. Livermore at the center of Angel Island. After checking out views from the peak, continue on the southern Ida Trail to the fire road that circles the peak. Turn right onto the fire road and continue to Four Corners where you'll hit the paved trail. Walk past the Nike Missile site then up to the hospital at Fort McDowell for a roundtrip hike approximately five miles long. // Angel Island State Park (Tiburon), parks.ca.gov

A historic barn at Pierce Point Ranch, at the head of the Tomales Point Trail.(Courtesy of Tomales Point Trail)

Tule Elk Reserve

The Tule Elk Reserve is, hands down, one of the best places for a long day hike in the Bay Area. Not only does the 9.7 mile roundtrip Tomales Point Trail offer spectacular views of Tomales Bay and up-close sightings of the wild tule elk, which were returned to this part of the coast in the 1970s, but the whole thing kicks off with a romp through a historic dairy and ranch. The Pierce Point Ranch, at the trailhead next to the parking lot, dates to 1858. Solomon Pierce, who bought the property for $7,000 in 1858, produced high quality butter sold in Gold Rush-era San Francisco. The isolated ranch once housed the Pierce family and the families of its workers; many of its abandoned buildings—including the schoolhouse, blacksmith shop, dairy houses, barns—are still standing and open to exploration. Pro tip: To get there, follow the instructions on the National Park Service website—GPS will send you on a wild elk chase. // Pierce Point Ranch at Pierce Point Road 9 (Inverness), nps.gov

The quicksilver tramway track at Almaden Quicksilver County Park.(Courtesy of Almaden Quicksilver County Park)

Almaden Quicksilver County Park

The second largest mercury (quicksilver) mine in the world was once located in the South Bay. The liquid metal from what is now Almaden Quicksilver County Park was commercially dug as far back as 1845 to be used in everything from Civil War explosives to thermometers to gold extraction in the Sierra Nevada. On a 5.1-mile roundtrip hike through the park, you'll pass the remnants of the once-booming mine camp, including the entrances to mining shafts, old pumps and furnaces, a tramway, and the infamous hanging tree where swift justice was once meted out to lawbreakers. From the Hacienda park entrance, follow the southern Deep Gulch Trail to the Yellow Kid Trail. At "Spanish Town," head west along the Castillero Trail near the Catherine Tunnel and onto the Mine Hill Trail to complete the loop. An online guide put together by Boy Scout Troop 466 describes in detail the landmarks on the route. If you're looking for a shorter or longer hike, other mine remains are visible from almost every trail in the park. Dive deeper into mining history at the Casa Grande and Almaden Quicksilver Mining Museum on your way out of the park. // 21785 Almaden Rd (San Jose), sccgov.org

The abandoned lightkeeper's house on the island at Ano Nuevo State Park.(Courtesy of Ano Nuevo State Park)

Año Nuevo State Park

Most people know Pescadero's Año Nuevo State Park for its elephant seal breeding and molting grounds, but this coastal preserve has a fascinating cultural history to rival its natural one. The Quiroste, an Ohlone Indian group, inhabited the region long before the arrival of the first Spanish settlers and their settlement at Año Nuevo, rich in the valuable resources Monterey chert and olivella shells, was among their wealthiest. After Spanish missionaries subjugated the area in the 18th century, Año Nuevo became a cattle ranch and, in 1862, a dairy. Beginning in 1872, a complex that included a lighthouse, an elaborate lightkeeper's home, tramway, boathouse and dock were built on Año Nuevo Island, where ships were prone to run aground on rocky outcroppings. Though the lighthouse complex is not open to the public, its creepy, abandoned buildings are visible from shore. For a taste of three centuries of Año Nuevo history, start at the parking lot near the Marine Education Center. From there, walk south along the short Steele Trail past the historic Dickerman-Steel House. At the New Years Creek Trail, turn right and continue on to hook up with the Año Nuevo Point Trail. Continue north past Bight Beach along the Año Nuevo Point Trail to catch views of the abandoned buildings of Año Nuevo Island and the elephant seal colony. Return the way you came to complete the 4.2 mile out-and-back trail. During elephant seal breeding season (mid-December 15 through March), most of the trail is only open to visitors on guided tours ($7). A (free) permit is required all other months of the year and can be requested when you enter the park. // 1 New Years Creek Rd (Pescadero), parks.ca.gov

Nike Missile Site SF-51 on the Sweeney Ridge Trail.(Courtesy of Sweeney Ridge Trail)

Sweeney Ridge Trail

The Sweeney Ridge Trail in the southern section of the Golden Gate National Recreation Area contains two important historical sites. It's easy to miss the first, a stone monument commemorating the location where the 60-man expedition led by Captain Gaspar de Portola first sighted the San Francisco Bay in 1769. The second, Nike Missile Site SF-51, a Cold War–era battery now abandoned and covered in graffiti, is a little more obvious. To see both sites, you have two possible starting points: From the Skyline College parking lot, hike the Notch Trail south to the Sweeney Ridge Trail; or from the parking lot at Shelldance Nursery, take the Mori Ridge Trail to the Sweeney Ridge Trail. Both easy-to-follow trails are five to six miles long, out-and-back. // 3660 Sneath Ln (San Bruno), nps.gov

Historic lime kilns at Wilder Ranch State Park.(Courtesy of Michael Popham)

Wilder Ranch State Park

Wilder Ranch State Park in Santa Cruz is a center of living history that draws thousands of visitors annually to events such as their Old-Fashioned 1900s Independence Day. The park's history as a working ranch and dairy are on full display the moment you arrive, but it's only on the trail that you'll find evidence of the area's once important role in the lime manufacturing industry. Lime kilns operated here from around 1858 to 1909, and remains of the structures are still visible near the trails on the eastern side of the park. From the parking area, head up the right (east) side of the Engelsmans Loop trail. At the junction of Engelsmans and the Long Meadow Trail, a short, unmarked trail will lead you to the historic ruins. When you're done snooping around, take a second detour onto Old Cabin Trail near the junction to see the remains of several old logging cabins. Backtrack to the junction and then return south on the Engelsmans Loop Trail towards the coast to complete the approximately four-mile hike. // 1401 Coast Rd (Santa Cruz), parks.ca.gov