Antifreeze

Antifreeze is a Halo 5: Guardians multiplayer map created in Forge, released on December 16, 2015 as part of the Cartographer's Gift update. It notably includes every Forerunner weapon in Halo 5: Guardians.

Trivia
The map was initially meant to be based off the Halo: Combat Evolved map Sidewinder and the Halo 3 map Avalanche, but turned out completely different, hence the name antifreeze.