The population of Ecuador's capital Quito has grown sevenfold between 1950 and 2001. There are three types of slums in the city, namely barrios periféricos (shanty towns on the edge of the city), conventillos (dilapidated tenements in the urban centre) and rural shanty towns from where inhabitants commute to work in the city. An estimated 170,000 people were living in slums in 1992. In Guayaquil, Ecuador's largest city and main port, around 600,000 people were either squatting on self-built structures over swamplands or living in inner city slums in the early 1980s. Illegal settlements frequently resulted from land invasions, in which large groups of squatters would build structures and hope to prevent eviction through strength in numbers.