The Elysium server thanks to help of Bukkit has grown to encompass multiple worlds and is truly a multiverse!

Elysium:

This is the base world and is the one where all new players arrive in, from there they may choose their path and forge their journey in the minecraft universe. This being the original server world it is the oldest and biggest of the worlds with some very fantastic and amazing sights, this world does not have any hostile mobs and is more a creative server.

Tartarus:

Tartarus is the world where all the monsters from Elysium were sent…banished to remained there for all of eternity. As you might expect this has not made them very happy and they take extra pleasure in blowing up and murdering any mortal fool who would dare step foot into Tartarus. This world is 24/7 survival mode and many of the amenities and conveniences found in Elysium are not present here, Inventories are also separate and you cannot take your Elysium inventory to Tartarus and vice versa.

Styx:

The Styx is a Nether world connected to the Elysium world, it can be accessed one of two ways. The first is to drop down the hole at the spawn point and the second is to visit /warp hellroad

Once in hellroad simply follow the road down into hell, jump in the pool of water to go to Styx.

Hades:

Exactly the same as Styx only this Nether world is connected to Tartarus and can be accessed by going through the portal with the flaming horns at the spawn point.