Keep em comming, guys.
MarkC, to answer your last question, because it would effect any games you might start in the meantime, they don't hide from others, although in Uzarag certain areas are fallow enough that you don't always spot the door. In the living Dwaven kingdoms, the entrances are obvious by the big walls and defenses you have to go through to get to them.
I should answer the one before that too, for the same reason. Most people walk into a dwarven kingdom through a pass, taking a road to the gates of one of the cities (or fortresses, if they have a right to be there). Inside the city, there are usually underground roads connecting to other cities, or you can go back out the way you came and take surface roads. The gates themselves usually look like doors for small settlements all the way up to major fortresses for cities (but that's just the gatehouse, if you say a dwarven fortress, you're probably looking at a couple of rings of walls surrounding a door. The fortress is underground.) Most settlements and fortresses have a second postern entrance, and THAT's hidden, usually accessed by a hidden road (think the campy version of Batman with Adam West for how you hide a road, but make it less silly.)