You had to see it to believe it. These were the original bunkers at A4. The ones at C2 were not much better. Built by the USMC when they called it Con Tien the bunkers took an awful beating from NVA rockets and artillery. And they never received any repair work. They were dark, filled with rats and in many cases structurally unsafe. 1/61 with Engineer help either rebuilt or replaced most of these original bunkers but not before having to spend many nights in them while rockets landed.
This is the entrance to one of the main bunkers. You can see how the wooden beams around the door is sagging (the wood was rotten with age) and the green sandbags have given up and are now mostly rags that blow in the wind.