This map(MC v1.2.3) has 2 features.
Best Viewed with Johnsmith Texture pack. Get it here http://www.minecraftforum.net/topic/26727-johnsmith-texture-pack-v92-32x-12-with-customizer-0301/

First off there is a Starship high above made by myself. The ship is complete with power core, main bridge, secondary bridge, quarters, cannons, galley, captains quarters, 2 cargo bays, and 2 fighter hangers.
Inspired by Star Trek, Star Gate and Battlestar Galactica.

Second is below. An automated Mob arena Version 1 Built by Aracongi with some help from Syntacks. This thing is complex! sleep in the bed near the entrance, flick the switch (mine cart up top will start to circulate meaning it is working) and enter the mob arena. This version is a work in progress but is working as is. fight zombies, skeletons, and cave spiders. There is no exit once in the arena atm.

I have been working on another update for Holodeck (http://www.minecraftworldmap.com/worlds/UOBK6
last updated Feb 27 2012: http://www.minecraftworldmap.com/worlds/7eMrs) and here is a preview of another coming update. My way of saying

Thanks for 500 downloads.

Preview includes a Minecraft 1.2.3 version of a ship in the coming 'Holodeck' update complete with captains quarters, map room, crew beds, many cannons, galley, prison cells, cargo and cargo hold, and more.