The bridge consists of two crossings, east and west of Yerba Buena Island, a natural mid-bay outcropping inside San Francisco city limits. The western crossing between Yerba Buena and downtown San Francisco has two complete suspension spans connected at a center anchorage. Rincon Hill is the western anchorage and touch-down for the San Francisco landing of the bridge connected by three shorter truss spans. The eastern crossing, between Yerba Buena Island and Oakland, was a cantilever bridge with a double-tower span, five medium truss spans, and a 14-section truss causeway. Due to earthquake concerns, the eastern crossing was replaced by a new crossing that opened on Labor Day 2013. On Yerba Buena Island, the double-decked crossing is a concrete viaduct east of the west span's cable anchorage, the Yerba Buena Tunnel through the island's rocky central hill, another concrete viaduct, and a longer curved high-level steel truss viaduct that spans the final to the cantilever bridge.