The lacustrine landscape of Xochimilco, located 28 km south of the city, constitutes the only reminder of traditional Pre-Hispanic land-use in the lagoons of the Mexico City basin. The latest archaeological finds at the Templo Mayor (the Aztec Main Temple) in the Historic Centre of Mexico City contribute further to the understanding of the pre-Hispanic city. However, the integrity of the Historic Centre of Mexico City and Xochimilco is vulnerable to threats derived from the geological conditions of the place. In the Historic Centre the Authority for the Historic Centre (Autoridad del Centro Histórico) and the Historic Centre Trust Fund (Fideicomiso Centro Histórico de la Ciudad de México) were created to support conservation and management activities in the Historic Centre. In the case of Xochimilco, the city government of Mexico City published a decree on 11 December 2012, in which “The Authority in the zone of Natural and Cultural Heritage of Humanity in Xochimilco, Tlahuac and Milpa Alta” was created.