Sure you can. Towerwood takes a long time to break (it's like the obsidian of wood), but keep chopping at it with an axe for maybe 20 or 30 seconds and you can get in. Items and devices that can break blocks instantly (turtles, wand of equal trade, mining laser, etc.) can also be used to break/collect the blocks. Don't expect to find much inside, though, or you'll be disappointed - it's a WIP, and mostly empty at the moment. At least it has some nice blocks, if you don't mind building with something that takes FOREVER to break by normal means.