A heavy seacoast gun sits on its disappearing carriage within a concrete emplacement, part of the extensive harbor defense fortifications built by the U.S. Army Coast Artillery Corps to protect Manila Bay in the early 20th century. Forts such as Corregidor, Drum, and Frank mounted guns of this type, which could be lowered behind their parapets to reload, out of enemy view, before rising again to fire. Project: 218608