Ten million years ago, lava flowed through the East Bay hills from an active volcano, which flows from Tilden Park’s Inspiration Point to Moraga. Today, Round Top volcano is the most prominent feature of the Sibley Volcanic Regional Preserve, rising 1,763 feet above sea level. Dedicated in 1936, the preserve is one of the oldest parks in the East Bay Regional Park District. The area was once the center of extensive quarrying activities, and the preserve is best known today for the enigmatic labyrinths that existed at the bottom of the canyons of the quarry.

This walk of about 2 1/2 miles takes you past two of the labyrinths. The preserve is a popular place for dog-walking, so you’ll see lots of dogs, mostly well behaved and leashed. There are also a fair number of cows, so watch where you step.

In the hills above Oakland, California, the Robert Sibley Volcanic Regional Preserve is dotted with labyrinths of different sizes and complexities.

On the many paths and pathways of this former (10 million +/- years ago) volcanic ridge, these meditative mazes are a joy to explore. Superlative views of Oakland, San Francisco, and the Bay are also offered by the trails.

Head towards the Volcanic Trail via the Round Top Loop Trail from the Sibley Staging Point, just off Skyline Boulevard. In quarry pits and scattered in the grassy hills along the road, keep your eyes out for labyrinths.

This amazing attraction is located near the following must-see parks in Orinda, California:

  • Orinda Oaks Park
  • Orinda Community Center Park & Tennis Courts
  • Briones Overlook Staging Area
  • Siesta Valley Recreation Area
  • Old San Pablo Trail
  • Seaview Trailhead
  • Bear Creek Staging Area
  • Tilden Regional Park

All of these landmarks are located just a short distance from our location in downtown Walnut Creek, Spaulding Concrete on Locust Street!

The Labyrinths

From the top is visible the largest and most complex of the labyrinths, and it’s the only one that we know for sure was not created by extraterrestrials. It is the Mazzariello labyrinth, built as a gift to the world by East Bay resident Helena Mazzariello in 1989. It is a true labyrinth, meaning that rather than a maze, it has only one route to the middle, which provides many options. You can take the route down to the maze or (carefully) walk along the top of the quarry, peering into its depths.

 Return to the Round Top Loop Trail to see a second labyrinth, before it bends to the left to complete its loop. Enjoy the views of Tilden Park and continue straight on the Volcanic Trail, which was once the quarry haul path. You can see a numbered post when the Quarry Trail intersects on the left, matching the numbered stops on the self-guided tour. At No. 5, the second labyrinth is (No. 7 on older maps). Look down at a delicate, heart-shaped maze in the quarry, smaller and maybe more elusive than the first.

 To see the remainder of the numbered stops on the self-guided tour, you can continue along the Volcanic Trail or return to the Round Top Loop Trail, carrying right to complete the loop and return to the parking lot.

Getting There

Cross the Bay Bridge by car from San Francisco, and travel east on Interstate 580 towards Highway 24. Take Highway 24 east to Walnut Creek. Take the Claremont Avenue exit from here (Exit 3) and turn left. Stay on Claremont Avenue (do not turn left on Claremont Boulevard) past Ashby Avenue, and proceed on Claremont Avenue until Grizzly Peak Boulevard intersects. Turn right and continue until it ends at Skyline Boulevard on Grizzly Peak. On Skyline, turn left and then immediately left into the Sibley parking lot.