Suisun Bay (pronounced "soo-soon") is a shallow tidal estuary located at 38°04?N 122°04?W? / ?38.07°N 122.07°W? / 38.07; -122.07[1] in central California, USA. It lies at the confluence of the Sacramento and San Joaquin Rivers, thus forming the entrance to the Sacramento-San Joaquin River Delta, an inverted river delta. Suisun Marsh is the tidal marsh land located to the north of the bay. It is the largest marsh in California.