Yeah they were usually just a boring circle. But there was a time around 2007 in Iraq I traveled through a combat outpost that was made with 15 meter high conc

Yeah they were usually just a boring circle. But there was a time around 2007 in Iraq I traveled through a combat outpost that was made with 15 meter high concrete walls and had turrets (which also held guns) on 4 sides. It was a proper little castle. Though the enemy in Iraq did have a lot of mortars so the patrols stationed did see causalities from indirect fire.