Sunol is a small, unincorporated community in southeastern Alameda County, California, tucked into the Sunol Valley between the San Francisco Bay's southern tip and the Livermore Valley. Its census-designated place had 922 residents at the 2020 census, and the broader Sunol area covers roughly 86 square miles, an expanse of oak-studded hills, ranchland, and open space about the size of San Francisco. The community is deliberately rural, with just a handful of main roads and a pace that stands apart from the suburban East Bay that surrounds it. The town's identity is tied to two long-standing institutions. The Sunol Regional Wilderness, operated by the East Bay Regional Park District, preserves thousands of acres of the surrounding hills for hiking, camping, and nature study, anchored by the Green Barn Visitor Center. The Niles Canyon Railway, an operating railroad museum, runs historic steam and diesel trains through Niles Canyon between Sunol and Fremont on select weekends, drawing visitors to the canyon's railroad history. Sunol grew around water and rail. The community lies along Alameda Creek and Niles Canyon Road, a designated scenic route that follows State Route 84 through the canyon toward Fremont. Interstate 680 runs along the valley's eastern edge, and the Altamont Commuter Express rail line passes through the Sunol Valley on its route between the San Jose area and the San Joaquin Valley. Public education is provided by the Sunol Glen Unified School District, a single-school district serving transitional-kindergarten through eighth grade, with graduates attending Foothill High School in the Pleasanton Unified School District. This small-school structure, combined with the valley's open landscape, is central to Sunol's character as a quiet, close-knit rural enclave within one of the Bay Area's most populated counties. Residents prize the combination of open space, wildlife, and a short drive to Fremont, Pleasanton, and Livermore, and the community has long guarded its rural identity amid regional growth.