According to the Orlando Tourism Bureau, Orlando hosted 47 million domestic and international visitors in 2009 (the most recent year available).? Includes comprehensive coverage?on the Wizarding World of Harry Potter which opened in 2010 Both Universal Orlando?? and SeaWorld??remain?in the top?theme parks to visit in the?United States- each with attendance of almost 5?million in 2009.? Universal Orlando's Islands of Adventure attendance is expected to increase with the much anticipated arrival of the Wizarding World of Harry Potter