Trinity Apartments, a six-story, three-tiered complex that sits atop a ridge in Auckland, New Zealand's trendy Parnell neighborhood. The concrete, glass, and cedar structure with 32 roomy apartments (ranging from 750 to 2,350 square feet) is not only striking to look at, but engineered to harness natural light, warmth, and an abundance of cooling breezes. Photo by Simon Devitt.  Photo 1 of 8 in Density Down Under