In the Habitat Agenda adopted in 1996, heads of state and governments committed themselves to two main goals, i.e., “Adequate Shelter for All” and “Sustainable Human Settlements in an Urbanizing World”, and to implement a plan of action based on these goals. In the Millennium Declaration, heads of state and governments committed themselves to improve the lives of at least 100 million slum dwellers by 2020. They also committed themselves to halve, by 2015, the proportion of the population without adequate sustainable access to drinking water and basic sanitation.