The camps were all crisscrossed with networks of bunkers, trenches, and firing positions. Positions within each strongpoint were interconnected by trenches and tunnels. Both sides began to construct defensive positions reinforced by dugouts, trenches and barbed wire. Both sides then started setting up trenches and fortifications. Destroying bridges, blocking roads, creating airstrips, digging trenches, etc. Malebolge is a large, funnel-shaped cavern, itself divided into ten concentric circular trenches or ditches. Many soldiers were fearful of rats more so than other horrors found in the trenches. Shoring also has to be taken into consideration for larger trenches or pits. Around 75 percent of known casualties in the trenches came from artillery shell fire. Equally it could be used as light artillery in bombarding distant trenches. It includes the Great War Open Air Museum with its trenches and tunnels. They were unable to traverse a battlefield obstructed by craters, barbed wire, and trenches. Temple structures were built on foundations of stone slabs set into sand-filled trenches. Various mechanical devices were invented for throwing hand grenades into enemy trenches. There are cold, deep ocean trenches.