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
Ancient Ruins and Archaeology Quarterly", and "Travel". The work is a guide to a dozen of the more famous ruins from civilizations of ancient times throughout the world, the speculations surrounding their fates, and modern fantasy literature inspired by them. The surveyed sites include Tartessos, the Pyramids of Giza, Stonehenge, Troy, Ma'rib, Zimbabwe, Tintagel, Angkor, the Mayan city of Tikal, the Inca city of Machu Picchu, Nan Matol, and the Moai of Rapa Nui. Francis D. Lazenby, in the "Library Journal", called the book a "highly literate volume" whose "fascinating" accounts "are not simply another retelling: unusual material is added, and in very readable