I decided to try and build a fortress losely based on the Channelwood Age storyline in Myst, as written and described by Atrus. I picked an embark site with tons of trees (lots of cherry trees, the dorfs and I like them for their blossoms), and very selectively chopped trees. I used the wood to create an entire tree based fortress. I built three skinny towers to preserve wood, making just enough room for a double staircase. The main tower stands 13 z levels tall. The "stem" or tower part is 4x4 and goes straight up through the tree canopy. There is a bird observation deck at z-level 6 (I see some really cool stuff flying at that level) and at the top level (the first z-level that clears all tree canopy, level 13) I first constructed a 14x14 tavern in the sky, I am working on making windows right now to replace some of the walls. It contains some decent statues and even a display case with a red panda boar figurine of artifact quality, that one of my dorfs made. Above the tavern is a somewhat shady storage area where the tavern keeper stores rum barrels but where the expedition leader also made himself a small office and sleeping quarters right above the tavern.
The top level also holds guest barracks for tavern visitors and I am in the process of building more office space up there. There are two other towers, all three towers are set apart from eachother quite a bit but are connected to eachother on several levels using drawbridges. The two smaller towers are only 3x3 and only go up 8 and 9 z-levels respectively. I currently use one of the small towers for my chicken egg production (10 chickens, 2 roosters now). Building in the sky takes tons of wood though (floors/ceilings), and I want to preserve the towers being surrounded by trees and such. For rp reasons I don't really want to build up there with heavy stone.
To my amazement I started noticing that where the tree branches touch my buildings, dorfs have started using the trees to go down the building, though they always seem to take the stairway up the tower, they must prefer climbing down over climbing up.
Plans for tonight:
1) Build a pump stack attached to the tall tower and bring fresh water to level 13
2) Learn to build windmills and see if I can place some at the top of my tower, on a platform. Seems like it should by nice and windy up there
3) Look into using DFHack to place farmable squares/dirt on a floor surface up in my towers. I'd like to try and RP a story about dorfs that became tree-dwellers and gave up on surface life . I wish I could use the pit/pond command to not only move water but also be able to fill a pit or pond with farmable wet sand or loam or something.
4) If you can put dorfs in a drown tank and slowly raise the water level to 3-4 you can teach swimming, is there a way to teach the climbing skill by forcing dorfs to climb.
I also made a sparrow man in Adventurer. He is a Master level elite Biter and amazing bookbinder, I might try and link him to my fortress, Mobgem.