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
Machu Picchu northwest edge of the rock platform points out the Solstice Window to within 2’ of the 15th century June solstice rising Sun. For comparison, the angular diameter of the Sun is 6'. The Inca constellation Qullca, storehouse, can be viewed out the Qullqa Window at sunset during the 15th century June Solstice, hence the window's name. At the same time, the Pleaides are in the opposite end of the sky. Also seen through this window on this night are the constellations Llamacnawin, Llama, Unallamacha, Machacuay, and the star Pachapacariq Chaska (Canopus). The "Intihuatana" stone is one of many ritual stones