Welcome to San Juan! Before you start your adventure, it's always handy to know some facts about where you're headed. So unfold your map, grab a pen and listen up.San Juan is an island of United States of America. Its shimmering shorelines and fresh salty breezes await!If you'd like to get some local tips on things to see and do, you shouldn't have too much trouble. It's home to approximately 36,600 friendly people who'll be happy to point you in the right direction.