Siege maps - climb walls problem

[Sara Temer]

I'm trying to figure out how to create siege maps in TEd (atm. I use only vanilla assets) and I have no idea how to make walls climbable. I added "Zone" in place where walls are and "Go Region" around castle (like it is in case of vanilla castles). But I don't have option to order units to climb walls while test castle. There's any additional step which I need to do?

[LawAbidingGypsy]

You need to enclose the walls. There must be a complete ring of walls and/or no go zones. After this, all wall must be at the same absolute elevation and aligned perfectly. For this, it's best to enable snaps and to choose a specific height and stick with it.