There are several river islands in Washington, D.C., including Theodore Roosevelt Island in the Potomac River, which hosts the Theodore Roosevelt National Memorial and a number of trails. Columbia Island, also in the Potomac, is home to the Lyndon Baines Johnson Memorial Grove, the Navy – Merchant Marine Memorial, and a marina. Kingman Island, in the Anacostia River, is home to Langston Golf Course and a public park with trails.