Started with a small 11x11 above ground walls for the Depot, then covered the 30x20 pasture around my 3x3 central stairs.
I have lots of logs in this wilderness embark, so I made the walls 2-z high.
Hmm, sapplings are growing around the wall perimeters, so instead of using constructed floors at 1 log each, I opt for constucted road using 1 log for 3 tiles, or 3 logs for 10 tiles (a great discount!)
A goblin siege, 1 trapped while 2 stuck waiting on the south ramp entrance.
2 trapped while 3 stuck waiting on the west ramp entrance.
A titan, blob of flame arrives in the west.
At first, titan chased and shoot fireballs at a herd of kangaroos roaming SW.
The chase pathed the entire SW to SE, fire ablazed!
After the herd, titan path's toward my fortress, sees the goblins on the south, torched the wooden cage trap and eventually the goblin got freed only to get burned.
I have minimal military, opting for a tunnel and bridge of cage traps in my NE. But no one is visiting there!
/facepalm, in my awe at the fireballs vs kangaroo, I forgot I left the hatch unlocked to invite the goblins to path in. Doh!
Lots of smoke in the south but no path anymore, and titan eventually swung west to the other goblins.
It burnt 3 more, but ignored the 2 caged ones?
/facepalm 2, there's still another hatch that is not forbidden in the west, not it is inside the pasture.
Wolverine (tamed) goes aflame! other beasts run north towards my tunnel/bridge cage traps.
In desperation, my 1 Axe, 1 Mace, 1 Spear, 1 Miner, and 4 Xbow recruits are mobilized.
2 bolts and the blob is gone. No kill count. Just that the bolts hits tearing tissue. Twice and blob is gone.
/facepalm 3, and when I thought I was safe, the 1 tile roads around my perimeter started burning.
But at least the walls and fortifications are indestructible. Just lots of smoke.
However, I spent the next 3 seasons getting spammed by "something in the surface collapsed."
Now only is the fire spreading all around me, it is burning on the z+ and collapsing tall trees.
I have at least 10 tile tree-less perimeter though.