They live on the edge of Lima - and of Peru's social structure. They are the abysmally poor of Lima's infamous barrios, the slum areas that ring this ancient capital city and stretch also along brackish streams from Lima to the port town of Callao, 16 miles away.
For half of the 5 million Limenos, it is a desperate day-to-day existence with little possibility of lifting oneself into something better.
Maria Gonzalez has lived in a two-room adobe hut next to a polluted stream for most of her adult life. She came here from a small, impoverished village near the colonial city of Ayacucho as a teen-ager, attracted by what proved the illusory promise of the bright lights of Lima.
She's the mother of 13 children, none of whom has the same father. She often feeds her brood on what she's foraged from Lima's garbage dumps. Each day is a challenge. But with the help of Jose, the father of her 13th child, she kept the family together as the children grew up.
The eldest child, now almost 30, did get out of the barrio, as have several of the others. But that was largely because a foreign visitor took a liking to the children and helped the family.
''For most of the people in these barrios,'' says Elvira Sanchez Bolos, ''that is a most unusual occurrence. For everyone who leaves, there are probably 500 others who never have a chance to get away.''
But the number of Peruvians who head for the city's barrios is growing. Hundreds of people from the countryside crowd into the barrios each day, Ms. Sanchez says.
The numbers of youth born to poor families in the barrios is surging, too. There is little birth control practiced. Peru's population growth rate is 3.1 percent a year, a rate that means the population is likely to double every 22 or 23 years.
Such growth makes it very difficult for Peruvian officials to resolve social problems in the barrios. How to bring simple services such as water and electricity, to say nothing of schools and clinics, to these areas is perhaps the basic challenge here - and across most of Latin America.
''The barrios are one of our worst problems,'' admits an adviser to President Fernando Belaunde Terry. ''There just isn't enough money for the social services needed to make these places more liveable.''
But as more and more people move into the barrios of Lima, there is a growing anger among the poor over the lack of services. Their anger also make them a prime target for political agitators who have encouraged a series of recent food riots by barrio dwellers.
''These riots are likely to grow in number and intensity,'' warns sociologist Sanchez.