Zip-line tours are becoming popular vacation activities. Some are as short as 100 feet while others may be as long as a mile. The jungles of Costa Rica, Florida, Puerto Vallarta,and Nicaragua are popular places for those interested in experiencing zip-lines. Since 2000, the number of zip-line tours in the United States has grown to over 200. Zip-line tours are not available at places such as Santa Catalina Island, Big Bear and the San Diego Zoo in California. Prices vary for the ride. The San Diego Zoo ride costs $112 (for two lines). At the Santa Paula, California KOA the cost is $10 for an 800 foot long zip-line. At Durango Colorado there are 27 zip lines totaling . The tour lasts for five hours.