The Contra Costa County Courthouse Block consists of the Vermont granite County Courthouse and jail and a low granite retaining wall which runs around much of the property, all dating to 1901. Originally, a short tower projected from the center of the roof and was surmounted by a dome. This feature was removed in 1957 after earthquake damage.

The buildings were very early examples of the Classical Revival architectural style in Contra Costa County. In the late 19th and early 20th century, classical styles were chosen because they were easily recognizable and understandable. Roman architecture stood for justice and Greek architecture for government.

The courthouse was designed by Havens & Topeke and the jail was designed by William S. Mosser & Son.

Adapted from the NRHP nomination submitted in December of 1989.