As San Juan nears the 500th anniversary of its founding, Arleen Pabon-Charneco explores the urban and architectural developments that have taken place over the last five centuries, transforming the site from a small Caribbean enclave to a sprawling modern capital.

As the oldest European settlement in the United States and second oldest in the Western Hemisphere, San Juan is an example of the experimentation that took place in the American "borderland" from 1519 to 1898, when Spanish sovereignty ended. The author also investigates post-1898 examples to explore how...