Vertigo Station
Can be found on EU battle.net through Multiplayer -> Create Game and searching Vertigo Station.
The entrance to each main base is narrow and easily defended. Natural expansions are blocked off by rocks from both sides. There's a second natural expansion on the other end of the entrance for each player. Long distances make early attacks difficult and air superiority is key. Xel'Naga towers oversee main attack paths and side expansions, which are rich but difficult to defend. The middle also has two rich expansions.
Version 1.2 addresses a few glitches with expansions and the central rich expos.