Machu Picchu on 1 April 2010. In July 2011, the Dirección Regional de Cultura Cusco (DRC) introduced new entrance rules to the citadel of Machu Picchu. The tougher entrance rules attempted to reduce the effect of tourism. The entrance was limited to 2,500 visitors per day, and the entrance to Huayna Picchu (within the citadel) was further restricted to 400 visitors per day. In May 2012, a team of UNESCO conservation experts called upon Peruvian authorities to take "emergency measures" to further stabilize the site's buffer zone and protect it from damage, particularly in the nearby town of Aguas Calientes, which had
Lost city few or no clues to their decline. For example, Malden Island, in the central Pacific, was deserted when first visited by Europeans in 1825, but the unsuspected presence of ruined temples and the remains of other structures found on the island indicate that a population of Polynesians had lived there for perhaps several generations some centuries earlier. Prolonged drought seems the most likely explanation for their demise and the remote nature of the island meant few visitors. With the development of archaeology and the application of modern techniques, many previously lost cities have been rediscovered. Machu Picchu is a pre-Columbian