Silver Strand is a low, narrow sandy isthmus in San Diego County stretching about 7 miles between Coronado and Imperial Beach. Whether understood as a natural isthmus or a human-constructed tombolo, it joins with Point Loma to shelter and define San Diego Bay. Part of it forms Silver Strand State Beach, whose ocean side includes 2.5 miles of coastline named for the silver shells found there. The strand is an important recreation corridor for jogging, bicycling, camping, surfing, swimming, boating, fishing, and other beach use, while adjacent beaches to the north and south are controlled by the Department of Defense and used extensively for Navy SEALs training.