Whether the idea was taken from monkeys or from Tarzan, zip-lines or canopies have become Costa Rica's ne w tour, where a vacationer can zip through the rainforest. The zip-lines are scattered among several platforms, some as high as 130 feet. Most often used as a means of entertainment, the longer and higher rides are often used as a means of accessing remote areas, such as a rainforest canopy. Zip-line tours are becoming popular vacation activities, found at outdoor adventure camps or upscale resorts, where they are usually one element on a larger challenge or ropes course.