Thin cliff walkways lead to and from each base. Expansions are safely hidden behind the starting locations. The lowest level of cliff is consumed by magma every three to four minutes, with warning. Dominion anti-air defensive structures are scattered across the center line, while the middle platform holds Kerrigan's chrysalis. If it is destroyed, she will be released onto the map and attack all players unless avoided or destroyed. Kerrigan is only vulnerable while submerged in magma. It is a large map, however, so moving around Kerrigan is only a matter of securing Xel'naga towers and keeping an eye on her.