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 drawings. It was used for rites or sacrifices. The Guardhouse is a three-sided building, with one of its long sides opening onto the Terrace of the Ceremonial Rock. The three-sided style of Inca architecture is known as the "wayrona" style. In 2005 and 2009, the University of Arkansas made detailed laser scans of the entire site and of the ruins at the top of the adjacent Huayna Picchu mountain. The scan data is available online for research purposes. This semicircular temple is built on the same rock overlying Bingham's "Royal Mausoleum", and is similar to the Temple of the Sun