Quicksand is a six-player map released with the SC2 launch and intended for 3v3 ladder play. It was removed from the ladder pool in February, 2011 because as Blizzard notes, "the only strategy teams can do on this map is rush, and the side with more mobility and that gathers its army the fastest wins".
Official Map Description
This is a small map. Watch for early attacks. Control the middle to gain additional resources. Low ground resources are hard to defend.
This map contains only one natural for each team, and three gold expansions, which lack any sort of defensive advantage due to terrain features, as well as one contested expansion at 8 o'clock. This map makes all expansions difficult to defend. Each base has a narrow choke, that makes early wall strategies simple and effective. There is a single Xel'Naga tower in the center that gives vision to most ground based attacks.