In an effort to do something different, I've been exploring the idea of a completely constructed above ground fort. Initially, I decided I'd try a game where I used the underground as a rock and ore source only, and constructed all my buildings from quarried rock.
I think I'm spoiled by the ease of tunneling out an underground fortress. While there's always a little challenge to getting the farming and distillation set up early, security is trivial. After things are stable, seal up the original quick entrance, and build a hallway of doom. There's only the one entrance, and flying creatures are only a threat to your surface farms - and you can wall and roof those for complete safety.
I took a couple of stabs at it by inverting my usual sub-surface approach, building stuff up rather than down, but still going through the same steps. The result was really, really slow to build and messy, and felt completely indefensible. While the surface entrance was secure, there were a million open spots above ground as I built new hallways. Leaving aside flying attackers, I imagine the first wave of goblin archers would be a disaster. The answer would seem to be a surrounding wall, but given how slow the basics have been to build, I just can't see how I'd spare the labor, particularly since it'd have to be a pretty tall wall.
How do you go about it? Forget the "I just build underground" answer, I've done that, I'm curious if this is just too much of a handicap.
- Gus