As people have become more aware of dwindling natural resources and the destruction of the environment, they have come to value what remains. Travel to national parks and other areas in order to admire Mother Nature's work is called eco-tourism. Visits to national parks have increased to the point that the government has been forced to reduce the number of visitors allowed in to ensure that the next generation will have something to admire. Many eco-tourism packages pro-vide guidelines to visitors on how to conduct themselves in order to preserve the natural beauty of the site they are visiting; for example, carry your trash out with you, and do not pocket any souvenirs