The Great Hall
U BASE, like its names suggests, is an underground base that's located not far from the 8BIT warp. Its main entrance is next to a Super Mario Bros. 3 sprite, and under a big floating sign that reads "U BASE". This base was an idea of Firefly300, and androids joined him in building and expanding it.
Inside the base, near the entrance, is located a maze built by androids. Despite its small size (21x21 blocks), it is quite hard to finish, because its layout is very confusing and chaotic.
Lighting in the maze is provided by Jack-O-Lanterns in the floor, therefore making it impossible to orientate oneself in the maze by the position of torches. The walls and ceiling are evenly made of iron blocks, whilst the entrance and exit of the maze are indicated by diamond blocks. The exit of the maze leads to the Hall of Flame.
As of January 10, 2011, it's not possible to solve the maze in reverse since its exit is one-way only. If you get stuck in the maze, rather than destroying blocks to get out, the command /wp androids maze can be used to teleport at the entrance of the maze.
Nothing special, just a couple of trees growing way below ground level.
The Great Hall, with its striped pattern, is where most of the base's rooms connect. Entrances to the Cave, the Hall of Flame, the Incinerator and the Rapid Transit.
Hall of Flame
The Hall of Flame was given its name because it's located near the exit of the Labyrinth.
The walls are made of non-flowing lava blocks. However, since lava will start flowing again on January 10, 2011, the room will have to be restructured so that the lava is safely contained behind glass walls.
Aperture Science Emergency Intelligence Incinerator
Since a wide range of materials are used in the construction of U BASE, our inventory is often full. Rather than using the /clean command, which results in our inventory being completely wiped out, regardless of which materials we'd like to keep, an incinerator was built to euthanize all unwanted items.
The Cave is a huge, almost 100% natural and totally awesome cave with lava lakes, waterfalls, and more. Stairs, fences and torches were added to make traveling in the cave easier.
M.O.T.I.O.N. Rapid Transit
What started with a simple experiment with minecarts eventually turned into a big rapid transit system. The name M.O.T.I.O.N. stands for "M.O.T.I.O.N. is not an acronym", and it's not an acronym. The metro line and stations were almost single-handedly built by androids, although Firefly300 helped, especially with digging (special thanks to Noxbene for his advice on minecart boosting).
There is currently only one metro line with two stations on an east-west axis, but it's continuously expanding. The tunnel is more than 300 blocks long. The two stations are U-BASE, the terminus at the west end of the line, and KAKARIKO, which is next to the construction site of the future Kakariko Graveyard, and near the Flash Man sprite from Mega Man 2.
When completed, the Rapid Transit will have two propulsion systems: minecart control blocks and minecart boosters. Control blocks are a more efficient and unobtrusive way of propelling minecarts. However, since CraftBook is continually being toggled on and off by the admins on the server, the rapid transit cannot rely solely on control blocks, or else it would be broken half of the time. Therefore, traditional minecart boosters are a fallback in case CraftBook is turned off.
As of January 10, 2011, the metro line is out-of-order because it is being redesigned in a more compact, efficient and beautiful way.