Starting in the early 2000s, the government has infused 500 million Mexican pesos (US$55 million) into the Historic Center Trust and entered into a partnership with the "Fundación Centro Histórico", an organization established by Carlos Slim, to buy dozens of centuries-old buildings for rehabilitation. The significance of this effort was recognized when, in 2006, the Historic Center was included in the 2006 World Monuments Watch by the World Monuments Fund. Work began with the beautification of 34 blocks just north of the Zócalo, digging up the antiquated drainage system and improving water supply. An architect was put in charge of each of the thirteen main streets to restore the facades of more than 500 buildings. The latest infrastructure projects of this type have focused on the southwest portions of the area, on República de El Salvador, Talavera, Correo Mayor, Mesones and Pino Suárez streets, mostly focusing on repaving and improving the outdated drainage systems. In the process, artifacts dating from as early as the pre-Hispanic period have been unearthed.