"Imperial Beach is a quiet, low-key beach town with a wide, sandy beach strand south of San Diego. The Tijuana River borders the south end of Imperial Beach. To the east is the expansive Tijuana Estuary National Wildlife Refuge. The Tijuana River watershed drains more than 1,700 square miles along the California-Mexico border, with its end point in the estuary. Barrier dunes, formed by sand traveling down river from the mountains, protect the estuary from the ocean forces. Wind and waves have sculpted the sand into dunes, while native vegetation stabilizes the dunes and holds them in place. Without the dunes, there would be no estuary. This hike straddles the dunes between the ocean and the estuary to the mouth of the Tijuana River, where it empties into the Pacific Ocean. Along the way are expansive coastal views extending north to Coronado and Point Loma, south to the hills of Mexico, and 12 miles seaward to the Coronado Islands."