Somersville (also, Sommerville and Summerville)[1] is an unincorporated ghost town in eastern Contra Costa County, California, United States.

Somersville's ruins have a fairly extensive number of graves in the Rose Hill Cemetery,[2] many of which are those of miners who died in the coal mines.

The Somersville mines are now sealed to prevent entry, due to frequent incidents of people becoming lost inside them during the mid 20th century.

The public school is maintained nearly all the year round, by a special tax when the State funds fails; from seventy-five to one hundred scholars being the average daily attendance.

The Public Broadcasting System examined the project in a 1980 episode of the anthropological documentary series Odyssey, titled "Other People's Garbage".