The Halo 3 Legendary Map Pack is available now on Xbox Live Marketplace for 600 points. To download the maps, go to the Marketplace section of the Start menu (press start in Halo 3 and click “Marketplace”) scroll until you find the Legendary Map Pack and exchange your hard earned wage for the map pack, which contains:
A medium-sized map designed for one-sided games ideal player counts range from 4 to 10 players. Ghost Town is the battle-scarred remnant of a war-ravaged hydroelectric plant in the foothills of Mt. Kilimanjaro.
Best Gametypes: Team Slayer, One Flag CTF, Multi-Flag CTF, One Bomb
A reimagingation of Halo: Combat Evolved fan favorite, Sidewinder, Avalanche’s size makes it ideal for big ol’ games of Halo 3. Avalanche is a Forerunner power station set on a glacial shelf on an under-construction replacement for Installation 04.
Best Gametypes: Multi-Flag CTF, One Flag CTF, One Bomb, Team King, Team Slayer
It's not a reimagination, it's a remake of one of Halo 2's most beloved maps. Blackout very nearly speaks the same language that its predecessor ,Lockout, spoke to Halo 2 players. Its long lines of sight and interconnected platforms preserved, but in a new location: a frigid UNSC research station beneath the low lights of the aurora borealis.
Best Gametypes: Team Slayer, One Flag CTF, One Bomb
For more on the Legendary Map Pack: