The city of Berkeley, California is located across a bay from what other city?

Berkeley is a city on the east shore of San Francisco Bay in northern Alameda County, California. It is named after the 18th-century Anglo-Irish bishop and philosopher George Berkeley. It borders the cities of Oakland and Emeryville to the south and the city of Albany and the unincorporated community of Kensington to the north. Its eastern border with Contra Costa County generally follows the ridge of the Berkeley Hills. The 2010 census recorded a population of 112,580. According to the United States Census Bureau the city's 17.7 square miles (46 km2) area includes 10.5 square miles (27 km2) of land and 7.2 square miles (19 km2) (40.83%) water, most of it part of San Francisco Bay.

On September 18, 2012, Berkeley became what may be the first city in the U.S. to officially proclaim a day recognizing bisexuals September 23, which is known as Celebrate Bisexuality Day. On September 2, 2014, the city council approved a measure to provide free medical marijuana to low-income patients. The Measure D soda tax was approved by Berkeley voters on November 4, 2014, the first such tax in the United States.

Berkeley is home to the oldest campus in the University of California system, the University of California, Berkeley, and to the Lawrence Berkeley National Laboratory. It also has the Graduate Theological Union, one of the largest religious studies institutions in the world. It is one of the most politically liberal cities in the United States.