The Cu Chi Tunnels are seventy five miles of interconnecting tunnels which were used by the Vietnamese army throughout the Vietnamese War (or American War as they call it). They served as hiding spots and as routes for interaction and supplies. A lot of troopers even lived in these tunnels https://jaredybyvc.alltdesign.com/how-much-you-need-to-expect-you-ll-pay-for-a-good-sai-gon-49526592