The Tijuana River Valley is known for its Regional Park and is located in the most southwestern portion of the City of San Diego. It is bounded on the east by Dairy Mart Road and the residential community of San Ysidro. It is west of Border Field State Park and the Tijuana Estuary. The southern tip of the valley is on the United States (U.S.)-Mexico International Border, at the north end is Sunset Avenue and the residential community of Otay-Nestor.
The Tijuana River which flows east to west from Mexico drains into the Pacific Ocean through the Tijuana River Estuary. The valley created by the river is known for its acreage of natural lands and habitats. The Tijuana River Valley Regional Park is composed of 71 and a half miles of dirt roads and pathways that have been created due to hiking of the highly vegetated area and/or horseback riding.