Hillsborough, CA

Hillsborough’s winding streets and large lots descend directly from its estate history. William Davis Merry Howard bought Rancho San Mateo in 1846, and later subdivisions brought San Francisco households to sizable Peninsula parcels. Residents incorporated in 1910 to prevent annexation by Burlingame and San Mateo, then used land-use rules to reserve the town for residential property. A half-acre minimum lot size adopted in 1953 remains in force. The town’s early layout favored curved roads and limited sidewalks over a standard grid. Hills, mature trees, widely spaced houses, and streets that follow the terrain now define much of Hillsborough’s 6.2 square miles.

ATTRH0n0r ( talk ) / CC BY-SA 3.0

Residential-only zoning places many routine destinations across the municipal line. Hillsborough residents qualify for cards at the Burlingame and San Mateo public libraries, which jointly serve as their library system. Shops and regional rail stations also sit in the neighboring downtowns. Moving through Hillsborough itself can be less direct than the map suggests. The Town Council adopted its first bicycle and pedestrian master plan on November 10, 2025. The plan records many hilly, winding streets lacking sidewalks or shoulders and identifies future connections toward Caltrain and the downtowns of Burlingame and San Mateo. Its recommended routes remain proposals until individual improvements are funded and built.

ATTRCayetano Arenas / Public domain

Schools and Town Hall supply many of the gathering places within the residential landscape. Recreation programs use the North and Crocker school campuses, and the annual Memorial Day event traces a civic route through town. The May 25, 2026 program placed the parade between Town Hall and North School, followed by music and a carnival on the school field. The estate era remains visible on a much grander scale at Carolands. French architect Ernest Sanson designed the 98-room chateau for Pullman heiress Harriett Pullman Carolan on an original 554-acre property. Listed on the National Register and designated a California landmark, the house preserves the scale that shaped Hillsborough long before school fields and Town Hall became its shared grounds.