The Portsmouth Naval Prison, a notoriously stern former U.S. Navy and Marine Corps prison on the grounds of the Portsmouth Naval Shipyard in Kittery, Maine -- across the Piscataqua River from Portsmouth, New Hampshire. The reinforced concrete, castle-like naval prison was occupied from 1908 until 1974. "Alcatraz of the East," as it was known, was modeled after Alcatraz in San Francisco Bay. Like the California facility, this enormous brig was deliberately set on an island with tidal currents to deter escape. Photo by Carol Highsmith, 2017.