I recently started a new fort because my old one was inefficiently designed. My new location has bloody cold winters where any unattended water will freeze instantly. This was pointed out in a very interesting fashion.
In my old fort I had a habit of toppling free-standing mesas by digging out the lowest level, channeling a pit under the remaining top, supported by a constructed floor and a support, then pulling the Demo-Lever(tm), causing the enormous lump of rock to fall neatly into the pit amidst a cloud of dust. And since the mesas were usually formed by a brook cutting through a cliffside, there was often a majestic fountain of water reaching one or two z-levels into the air, then falling back down, turning a large area of land into a temporary swamp. This time the lever was pulled in mid-winter in a rather chilly climate.
The fountain of water froze in mid-air. I'd post a few shots if I was patient enough to upload the pics. Nevertheless, it's quite an interesting sight. I wonder if I should go carve it into amusing shapes before the winter ends.
Next winter I'm trying the same thing on the nearby mesa, which is about 4-5 times larger than the one I just toppled.