Originally Posted by theelmerguy
I must say, those towers with the glass floors are epic. Who made those? How long did it take? I went down and saw the "Spider Dungeon" sign and immediately went back up. Way too scary. And where is a good place to hide that is totally safe? Are the towers safe even though they're open to the top? I read that hostiles can spawn anywhere!
The mostly-cobblestone tower with the spider dungeon at the bottom (and the adjacent house connected to it) is Bonn's. He used to have a sign up on the door to the house, but he must have either taken it down or it was blown up by a creeper.
Keeping signs at entries is an excellent way to keep ownership straight. Here's the crafting recipe for a sign. You can put signs on the side of most blocks or you can set them on the ground and they'll stick up on a post.
Like SpecMode said, hostile mobs can spawn pretty much anywhere it's dark. So, to be truly safe, you need torches, lightstone, or fires on top of the towers too. (I've cheated the local economy here a bit by giving a bunch of lightstone to Bonn; normally you can only gather lightstone from the hellish Nether zone, but the Nether doesn't currently work in multi-player.) The glass floors/ceilings are great because sunlight always
comes from directly above, even at dusk and dawn, meaning you can let daylight all the way deep into a cave both to use fewer torches and to indicate the time when you're far from the aboveground.