I started building a tree fort. You can find entrances at ground level and along the glass skyway. Please do not set it on fire.
It's still under construction. Assistance building it would be appreciated if there's anyone that bored. I have planted many, many trees in the vicinity of the fort for raw materials; they grow back faster than I can chop them down.
I'd like to build a trunk that goes nearly up to the top of the world, with a crown of live trees disguised cleverly at the top, but I've got a long way to go. Once that is finished I'll start to worry about the interior, branches, or decorations. I'd also like it to go underground quite a ways into a mine, though the risk of running into lava necessitates special care.
Inside of it is a chest and a bed. You're welcome to anything in the chest. If you wish to donate logs, that is where you should leave them.