Windy Hill Open Space Preserve is a regional park located in San Mateo County, California and operated by the Midpeninsula Regional Open Space District (MROSD). It is readily identifiable from the flatlands of the South Bay, as it is the only "naked" part of the peninsula range (not forested).
The Windy Hill Preserve comprises an important 1132 acre (4.6 km2) stretch of conservation land on the eastward side of the Peninsula Range (Santa Cruz Mountains), rising from the valley road near Portola Valley to the 1905 ft (581 m) summit from which it gets its name. Access to the summit is easy (0.5 mile moderate grade) from State Route 35, the ridge road along the Peninsula Range.