Atlantic Wall Regelbau 634 - Combat bunker with 6 Embrasure Armoured Copula Iron Turret. Armoured copula with six embrasures for machine guns. The sides of the copula are 25 cm thick. The muzzle of the machine gun was mounted in a ball head which fitted exactly into the embrasures. When the embrasures were not in use, they could be closed with heavy shutters. The hole in the top of the copula was for a periscope for surveying the terrain around the bunker. #bunker #Atlantikwall #Regelbau