Pulgas Ridge Open Space Preserve

Pulgas Ridge Open Space Preserve is a 366-acre preserve in the hills above San Carlos and Redwood City with about six miles of trails through cool canyons and up to a ridgetop with views of the bay. It is best known for its 17.5-acre off-leash dog area in the middle of the preserve, reached from the Cordilleras, Polly Geraci/Hassler, and Blue Oak trails; the area is signed but not fenced, owners must carry a leash and keep dogs under voice control, and dogs must be leashed everywhere else.

The Cordilleras Trail at the entrance is an easy-access path for wheelchairs and strollers, running 0.8 miles at a gentle grade through a meadow to a bench by Cordilleras Creek; the paved road beyond it gets steeper than 10 percent. For more exercise, a two-mile trail crosses the whole northern part of the preserve and is known for spring wildflowers, and the one-mile Polly Geraci Trail climbs through oaks into chaparral with views of the Santa Cruz Mountains, forming an easy two-mile loop. About 90 native plant species grow here, including giant trillium, mission bells, and Indian warrior.

The land was once the Hassler Health Home, a tuberculosis sanitarium run by the City of San Francisco; Midpen bought it in 1983 with help from a neighborhood assessment and demolished the buildings in 1985, though rock walls and steps remain. Bikes and horses are not allowed. The 25-space lot is on Edmonds Road, off Edgewood Road near Highway 280.