There are many questions about upgrading the severall buildings on top eleven.
I've found some picture who explains this a lot......
Maybe this could help some players.....

Click image for larger version.  Name: topeleveninfrastruktura.png  Views: 327  Size: 56.3 KB  ID: 4023

Is it handy enough for a sticky thread?
This week i will also make a better one with photoshop if there's enoug interest!

Greetzz