Since 1855, the Point Bonita Lighthouse has guided ships through the hazardous Golden Gate Strait into San Francisco Bay. It has stood through the passage of ships carrying California gold seekers, naval fleets departing for wars in the Philippines and Pacific Theater, and thousands of immigrants coming to the United States, and today it continues to greet mariners and visitors. Point Bonita is also known for exceptional geology, especially pillow basalt formed by underwater lava eruptions on the deep sea floor millions of years ago. Harbor seals live in the marine mammal sanctuary around Point Bonita, where they rest on nearby rocks and swim in Bonita Cove. Remnants of the Life Saving Station remain along the Point Bonita Trail, where surfmen once launched boats into rough waters to rescue vessels in distress.