Puerto Rico is a commonwealth of the U.S., so citizens do not need a passport to visit this island. This is a bustling island full of activities. Cities such as San Juan and Ponce offer lots of historical sites as well as great food and nightlife. There are lots of different kinds of beaches, making it equally attractive for surfers, snorkelers or people who simply want to relax. Puerto Rico also has quite a few casinos both large and small.