Last game - nice place, mostly sand, enough trees, few beasties (though there was a carp infestation, but fortunately 3zl down the waterfall). Got through 5 seasons, then read in wiki about mist generator -
http://dwarffortresswiki.net/index.php/File:Newmist.jpg. Set up large enough system of self-powered pumps. Next step - pour down some water in mist generator room, directly above large meeting hall with two thirds of entire population. As seen in picture, there is 1x1 pond.
So I thought - let's make here a well! And that pond will make perfect way to fill up well cistern.
One level below.
Well, first it happened that my machinery incapable of pouring down water in mist room
and powering up mist pump - some of water spilled down, wetting hall floor. Damn. OK, stop it all, mprove machinery, as well as closing mist holes with hatches, leaving only hole leading down to cistern. Done. Let's pour some water. And let's make some digging at other map edge...
Now, what will happen if you pour water down 4 z levels? Right, it'll easily come up one z level and flood entire fortress through well. And control levers are right behind flooded part of fortress. And water still comes... /facepalm
And some newer stuff - got idea of some sort of megaproject - find map with pit and sand, and cover pit with glass blocks to make floor adn ceiling. You know, bottomless pit under your feet... So I gen'd world, found map 5x5 with pit, magma, lot of other resources... and sandy clay instead of sand. FFFFUUUUU.....