Traditionally, the Fortress of Solitude is located in the Arctic, though more recent versions of the Superman comics have placed the Fortress in other locations, including the Antarctic, the Andes, and the Amazon rainforest. The general public in Superman's world is either unaware or at best only vaguely aware of the existence of the Fortress, and its location is kept secret from all but Superman's closest friends and allies (such as Lois Lane and Batman). A trademark of the Fortress is that it contains a memorial statue of Jor-El and Lara, Superman's Kryptonian parents, holding a large globe of Krypton. Although Superman has living quarters at the Fortress, his main residence is still Clark Kent's apartment in Metropolis. The arctic Fortress of Solitude concept was first created for pulp hero Doc Savage during the 1930s.