This is the worst wonder in the game IMO. It costs too many hammers, and 25% defense is a horrible bonus. Plus it expires at the point where it would actually be useful! It's better just to build Angkor Wat with your hammers....so useless. The only time I have ever built it is when I was playing an "RPC" as Pacal and one of the rules was that I had to build Chicken Itza, the Mayan wonder. What do you think of this useless wonder?