During the day, the parks that surrounded the monolith—each a tiny copse of trees ringed by perfectly manicured grass—were "safe zones." Watched over by Renraku’s gray-and-scarlet-clad security guards, they were places for the shaikujin who lived and worked in the arcology to stroll surrounded by something that resembled nature. By night, however, the security forces pulled back inside the walls and left the parks to the nocturnal denizens of Seattle.