With a volcano at its heart, Sibley Preserve is an unparalleled place to see Coast Range geology exposed as well as expansive views to the east and west.
Round Top, the highest point in Sibley Volcanic Regional Preserve and also one of the highest peaks in the Berkeley Hills, is a defunct 10-million-year-old volcano tilted on its side and exposed by erosion and past gravel quarrying activity. The area’s geologic past is evident in the rocks of the preserve and explained via a self-guided tour described in a brochure available at the staging area. Trails in the preserve reveal wildflowers in spring as well as two labyrinths tucked into former quarry pits. Sibley’s trails, which include a portion of the Bay Area Ridge Trail, connect to Tilden Regional Park in the north and to Huckleberry Botanic Regional Preserve and Redwood Regional Park in the south.