Drake's Ravine is an official skirmish map from Supreme Commander.
This is an enormous map with very wide open space separating two pairs of player positions. Gaining and eradicating your enemy at the top of each side can be exceptionally difficult. Wide open spaces in between are an ideal position to place strong points, but are also subject to sweeping air and land offensives from your enemy. T3 artillery places at the top of each plateau can easily sweep away many structures in the valley below.
This map experiences very heavy CPU loads even on 1v1 player. For some reason, the AI, including the newer modded AIs, consume many CPU cycles to conduct play.