The tourist industry is of special importance to Chicago, which has become the nation's leading convention center. Business travel accounts for about 36% of all state travel. In 2002, there were about 83.3 million domestic visitors to the state. Despite declines in overseas travel, Illinois was the 6th most popular US state for overseas visitors in 2002, with 1,071,000 travelers. The same year, Chicago was the 9th most popular US city for overseas visitors. Tourism and travel expenditures contributed about $22 billion dollars to the state economy. Over 300,000 people were employed in the industry.
Chicago's chief tourist attractions are its museums, restaurants, and shops. Chicago also boasts one of the world's tallest buildings, the Sears Tower, 110 stories and 1,454 feet (443 meters) high. There are 42 state parks, 4 state forests, 36,659 campsites, and 25 state recreation places. The Lincoln Home National Historic Site in Springfield was one of the state's most popular tourist attractions. Swimming, bicycling, hiking, camping, horseback riding, fishing, and motorboating are the most popular recreational activities. Even more popular than hunting is wildlife observation, an activity that engages millions of Illinoisans annually.