High Altitude Thirst!

High Altitude Thirst! is an achievement in Halo: The Master Chief Collection. It is unlocked by finding and destroying the BLAST soda can on Zenith Halo 2: Anniversary multiplayer. The achievement is worth 5 Gamerscore and can be unlocked in both matchmaking and custom games, though the latter is much more advisable. It also unlocks the "Zenith" Multiplayer Emblem.

Location
The can is sitting on a ledge beneath the Sniper Roost/Little Tower, below plane of the map.