ABOUT THE NEIGHBORHOOD. San Mateo is in San Mateo County, a beautiful area in the heart of Silicon Valley, California. Known for its diverse population and scenic landscapes, San Mateo boasts a variety of parks, recreational areas, and a vibrant downtown district that features a mix of shopping, dining, and cultural attractions. The city is well-regarded for its high-quality schools and community-oriented atmosphere. San Mateo's location on the San Francisco Peninsula provides easy access to San Francisco and San Jose, making it a strategically important suburban hub.