I came up with this in the process of working on a Byzantine/Middle Ages Mod and figured that the added defensive bonus provided by the Radiotower in modern times could be applied in medieval or even classical times by planting a troop garrison in strategic areas. Here's a view: It works just like a radio tower for a few reasons. First, taking into account that one 'Unit' is actually composed of many fighters, a garrison provides a refuge for fighters that have been on the front line too long. And since it is already manned by the workers/citizens/whatever that built the Garrison, these people would help to fill in the gaps when the Unit is weakened. Second, the 'Range', like a Radiotower, is effected by terrain because if a garrison were to be placed on a hilltop of mountain, it would be stronger and more effective. I've been working on a whole new line of techs, and I might post those later, but this becomes available with the advance 'Military Logistics', but this is only possible with another tech - 'Roman Roads'. I used Pounder's gravel roads to replace railroads (really because I couldn't figure out how to make an additional road type with a different movement bonus). I figured that my map is not much larger than Europe, and most turns are at least one year, so I can't see a deliberate move across Europe taking more than one turn - if there are well engineered and maintained roads, something the Romans knew how to do well. Here's a view of the buttons. It also has the button that I replaced the Watchtower with. I've attached the files for this and the Classical and American Western garrisons, from this post.