Fortifications (White Giant)

I keep purchasing fortifications and I'm at about 70, started at 30 or 40 but on my map, the fortifications don't seem to be showing up. Do I have to choose a location for them or anything? Or are they automatically built?

They often appear one on top of each other so it looks like ten is one. Customise your map and you can move them around individually to see them all, or you can turn on or off all forts, cities anything if you like and use different icons to get the look you want.

Thanks! I didn't realize that they built them on top of one another.