A self-governing commonwealth of the United States, Puerto Rico is comprised of one main island and several smaller islands and keys, the largest of which are Vieques, Culebra and Mona. The island of Puerto Rico is densely populated; with close to four million inhabitants, a diverse array of cultures and races are represented here. One-third of this population is concentrated in the capital city of San Juan. The official languages of Puerto Rico are Spanish and English.

Puerto Rico is home to El Yunque, the only tropical rainforest within the U.S. National Park Service and Río Camuy Cave Park, the third-largest underground cave system on earth. The astronomical observatory in Arecibo is the site of the world’s largest radio telescope. Puerto Rico’s Spanish colonial history is evident throughout the island, particularly in the capital city of San Juan.