As time went on, I spent some of my time supervising the upgrades of our current checkpoints with our builders. Well, not all of them were permanent but the ones that were permanent were given significant buffs.
These 'permanent' checkpoints were usually built on top of a bridge to make things extremely easier and the upgrades we put on were a watchtower, an airlock system for their gates, a communication system, and a 'filter' right underneath.
We used to just have platforms built a few feet up above the ground, and maybe a catwalk if it was built right next to a wall, but these watchtowers were built at least two-to-four stories high, depending on the location. If the location had just regular houses built around, a two-story watchtower was enough.
All we needed was enough height to spot hordes or anything unusual from a distance so the guards could either phone in a few groups to take care of them or just have them take care of the problem themselves.
I'm sorry for not uploading from the days gone because I just started p-playing... Days Gone... XD It's out on PC now and it plays well even if the movement is a little clunky at times
Still, I got so fucking hooked I finished the main storyline and I was just about to start new game+ before I stopped myself and wrote a chapter XD