I have had a sudden impulse to create a sprawling above ground city fashioned much like Minas Tirith in LOTR, and I thought it would be challenging and fun to play the game for the most part out in the open, and build an immense underground complex to fall back on in an emergency.
I have already erected the beginnings of two gaurd towers that enclose what will be my main gate, and have excavated a large mound to accomodate them. A sturdy wall 1 z-level tall (or two if I am ambitious) will encircle my mountain face, and fortifications will be built for my marksdwarves all along the wall, and a moat will ensure that my enemies will not get too close to it. My temporary barracks have been placed inside the gaurd towers' bottom stories, and my real barracks will be placed in opposition to the main gate (to ensure quick response) into the face of the mountain, extending a little inwards for an archery range. A road will zig-zag up said mountain (about 5 z-levels), and buildings will be placed along its face as the road twines upwards. Private bedrooms will line the third z-level mountain face in a multi-story apartment complex, thus adding extra road space on the higher levels. Fortifications will edge each cliff face for citizen safety and military convenience in case of a breach, and my trade depot will be in the far corner of the bottom of the mountain along with the workshops and stockpiles. A dining room and meeting hall will be erected directly under the apartments and into the mountain, and it will also serve as an entrance to the deeps by way of staircase. At the top of the mountain, a large nobles' hall and quarters will dominate the scenery, and a private tunnel will provide access to the second z-level for convenience and easy food reach.
Well, this is what I've got planned so far...
By all means, feel free to express your own ideas and opinions on the subject of above ground fortresses, and I would be happy to recieve comments and suggestions on my grand plan.
Oh, and I am building it as I go to discourage symmetry. I have a tendency to want to pre-plan and make everything symmetrical, but it gets boring real quick.