Abu Dhabi isn’t messing around with its plans to become the culture capital of the Persian Gulf: it has signed up several starchitects to design its signature buildings, and all of them will be built on a single undeveloped island off the coast. From Zaha Hadid’s swooping performing arts center to Frank Gehry’s Guggenheim, the designs reflect the truly unusual opportunity that has arisen from a city wishing to build a cultural district entirely from scratch.