Across the Cambodian border (less than 2 miles) was reputed to be the location of COSVIN; sort of like our Pentagon for the North Vietnamese Army. The armored unit we accompanied to this location took a day trip west into Cambodia and located concrete bunkers but no people. Four of our howitzers were towed behind the APC’s. We sat inline facing west, as the area off the road was swamp and jungle. FDC relied on pins stuck in the maps so we could use our tools to calculate settings for the guns. We forgot to bring any pins and borrowed safety pins from the grunts as substitutes.
We never learned how the road got there or why as it went from noplace to noplace.