Point Bonita Lighthouse guards the entrance to San Francisco Bay at a dangerous stretch near the Golden Gate, where wrecks during the California Gold Rush created an urgent need for a navigational aid. Built in 1855 high above the sea, the first lighthouse was often obscured by fog, so in 1877 it was moved to a lower site reached through a hand-cut tunnel for better visibility. The station also introduced the West Coast’s first fog signal. Its dramatic access route evolved from trail to walkway to suspension bridge as erosion and harsh weather repeatedly damaged approaches, yet the light remains maintained by the United States Coast Guard.