1. There's a stature with a holigram of Halo on top of it.
2. There's six areas in this map.
3. There's a tree with an energy sword in the middle of it.
4. There's a room a teleporters in it that lead to these platforms next to the tree. There's also another room with another teleporter.
5. There's a door that leads outside of the level. It has a tower in the background.
6. There's a door in the left and right directions of the area with the statue. They go to an area with a tunnel through the door on each side that goes up to the area with the tree.
7. There are also ramps that lead up to the area with the tree.
8. There are many doors in the area with the tree.

Most people have found a lot of skulls in halo 2 so I have wrote down the effects of some skulls I know about:

Legendary, armory, thunderstorm makes all covenant silver rank making legendary mode even harder.
Any difficulty, outskirts, blind skull disables HUD.
Legendary, metropolis, catch skull makes allies throw a lot of plasma grenades.
Legendary, the arbiter, grunt birthday party skull makes all covenant explode when they are killed by head shots.
Legendary, oracle, famine skull means weapons only have half ammo.
Legendary, delta halo, envy skull gives masterchief a cloak instead of flashlight and if you go through a checkpoint while cloaked and save then turn your xbox off and on again you will find yourself with and infinite cloak.
Legendary, regret, assassins skull makes all enemies cloaked even hunters jackals drones and brutes.
Legendary, qaurantine zone, sputnik skull makes explosions and melee have a better effect.
Legendary, gravemind, anger skull.....i think this means the brutes are stronger when they go berserk.
Legendary, high charity, iron skull means allies are immune to melee attacks.
Legendary, the great journey, black eye skull (i think) this means your sheild only recharges by melee attacking enemies and you can get your sheild way up to over sheild!