Sunol is an unincorporated area and census-designated place in Alameda County, California. Located in the Sunol Valley of the East Bay, the population was 913 at the 2010 census. It is best known as the location of the Sunol Water Temple and for its historic tourist railroad system, the Niles Canyon Railway.

The Sunol Water Temple is located at 505 Paloma Way in Sunol, California. Designed by Willis Polk, the 59 foot high classical pavilion is made up of twelve concrete Corinthian columns and a concrete ring girder that supports the conical wood and tile roof. Inside the temple, water originally from the Pleasanton well fields and Arroyo de la Laguna flowed into a white tiled cistern before plunging into a deeper water channel carrying water from the filter galleries to the Niles Aqueduct in Niles Canyon and across San Francisco Bay near the Dumbarton Bridge. The ceiling of the temple has panels with paintings by Yun Gee and other artists depicting a Native American maiden carrying water vessels, and women in classical poses. The temple is open to the public Monday to Friday, 9 a.m. to 3 p.m.