Citywall

On the city wall page you can upgrade the city wall. The city wall have 9 levels (0-8). Some levels increase the defense while other do nothing or increases the view radius around the city.

The citywall level is only known by the cityowner (while the city defense can be seen by all)

Citywall level	City defense strength	City view radius	Upgrade cost per level
0-2	0	2-3	50
3-5	5	3-4	100
6-7	10	5-6	200
8	15	7	400