antioch,_california | ispartof | contra_costa_county,_california <tsp> antioch,_california | ispartof | california <tsp> california | language | vietnamese_language <tsp> contra_costa_county,_california | ispartof | san_francisco_bay_area <sep> antioch is the third-largest city in contra costa county, california, united states the city is located in the east bay region of the san francisco bay area along the sacramento–san joaquin river delta the city's population was 115,291 at the 2020 census the city has grown substantially more diverse since the 1970s 
antioch is found in contra costa county which is part of the san francisco bay area. being located in california one of the languages spoken is vietnamese.antioch is located in the east bay region of the san francisco bay area