This large spiral labyrinth lies in an old quarry. It is one of many located in Sibley Volcanic Regional Preserve in the hills between Oakland and Orinda. It is thought to have been constructed in 1980s by Helen Mazzariello; and while the labyrinth was illegally installed on public lands, it has been allowed to remain.
The labyrinth is outlined with volcanic rock and through the years, plants have in among the rocks, it measures roughly 50 feet across. A number of visitors come to this maze, walking its path and leaving trinkets or personal offerings in the center. Rituals are also performed here. Visiting this spot, one must abide by the California Regional Park rules and only visit during park hours.