A few years ago, the Inca Trail to Machu Picchu was becoming the Long Island Expressway of central Peru, brimming with trash, tourists and growing concerns about overuse. So the Peruvian government began enforcing strict limits on the number of people allowed on the trail to the Lost City of Machu Picchu. Right now, only 500 people a day may enter — about 200 tourists and 300 guides and porters. http://ping.fm/B93Dr