Dodge down a side alley or through a narrow gap in the white-washed wall of a Manila street - or any other Asian city for that matter - and you will find yourself in another world, half medieval, half village.
On each side of a narrow lane or wooden walkway raised a few inches above the ground - many of the communities are built on low-lying ground - squat small houses. In many cases they are just huts, made of salvaged wood, cardboard, or galvanized iron. They shelter an average 10 people, most of them young, most of them living from hand to mouth. Kids seem to be everywhere: playing around the houses, looking after younger siblings, or carrying water in jerrycans from standpipes.
Between a quarter and a third of Manila's 6.4 million people live in squatter colonies. The enormous Tondo settlement, which houses up to one-quarter of a million people along the Manila foreshore, is said to be one of Asia's biggest slums.
Elsewhere in the city, small settlements perch above tributaries of the Pasig River or along railway tracks. New squatter houses sprout up overnight in vacant lots. It is hard to say exactly why the squatters come to Manila.
''We just hoped things might be better here,'' said Josie, who left her home province when she married three decades ago. ''First we went to Mindanao. The government was promising land free to anyone who could clear 15 hectares. But we could only finish nine, so we came here.''
A widow, Josie depends on one of three children for support. He is a scavenger, looking among trash bins and piles of garbage for anything reusable, like plastic bags or cardboard boxes.
Sociologists suggest that a wave of squatters moved into the capital when the price of sugar, one of the country's main commodities, collapsed in the mid-1970 s. A more positive attraction around the same time was the prospect of working on the building sites of the big hotels and conference centers that were promoted by the first lady, Imelda Marcos. The economy is depressed now, though, and work for the squatters has become even harder to find.
''My husband is a carpenter, he can make 25 pesos a day. But he can only find work about one or two days a week now,'' said Pasqualita, who has lived in Manila's slums for 30 years. She has seven children, three of whom are married and have been unemployed for ''about the last year.'' Three of the younger ones, aged from 10 to 17, support the family by working as newspaper vendors, darting among the cars stopped in jams or at traffic lights.
The government has tried many ways to solve the problem. First came resettlement. In the late 1960s and early 1970s, squatters were moved to new settlements like Carmona, 42 kilometers from Manila. The former squatters had no employment in the new areas, though, and had to face a long and costly trip to Manila each day. Many slipped back to the slums.
Then came on-site improvement - rather than push squatters out, encourage them to upgrade their homes. The largest on-site improvement program, in Tondo, is a source of great pride to the government's National Housing Authority.
The Tondo program, carried out with World Bank support, has just been finished, housing authority officials say, and has benefited about 52,400 people - between 20 and 25 percent of the slum's population.
But the authority was only able to help squatters with money: On average, families in the program pay back about 8,000 pesos at a rate of 70 a month, according to Maj. Gen. Gaudencio Tobias, general manager of the National Housing Authority. Those who can't pay have to make do.
''It's not really that bad,'' said General Tobias, ''eventually they'll fix things up themselves, little by little.''
During the past year, though, the government has become deeply concerned about the continued growth of squatter colonies. In mid-1982 it announced what it called its ''last campaign'' against slum dwellers. More than 200,000 slum dwellers in areas considered to be high risk - next to rivers that flood regularly, for example - and in prime sites for government development projects were to be moved out or sent back to the provinces by the end of the year.
''That was a bit optimistic,'' General Tobias conceded.
The anti-squatting campaign has now been extended to Oct. 1983 by which time it expects to have relocated over 30,000 families, including development of about 15,000 house lots in the resettlement area.
The plan has provoked widespread protest. ''It's just demolish and demolish, '' said Fr. Ted Butalid, who heads a Roman Catholic Church apostolate for poor settlers. In some cases, Fr. Butalid says, squatters have waited till demolition men leave an area, then promptly rebuilt their homes. ''But now we are getting reports that the demolition men are burning housing materials to prevent squatters rebuilding.''
General Tobias dismisses the protests as politically motivated. The dismantlement program - ''our crews are trained to dismantle, not demolish'' - has slowed down recently, he says, due to inclement weather, not protests.
In fact, another official of the housing authority says, the squatters' response to the program has been quite positive. In one place, the official says , ''squatter families have voluntarily dismantled their structures and are eager to be resettled.''
The squatters' enthusiasm is hard to understand, as the resettlement areas they are going to are in most cases the ones they rejected a decade or so ago. Unemployment in the areas is high: 46 percent in Carmona (renamed Gen. Mariano Alvarez), and averaging near 40 percent in the other sites, according to National Housing Authority documents.
The other option, returning to the provinces, does not seem popular with the squatters. ''I've got no family left in my home province,'' Pasqualita said, ''and people say work is even harder to find there than here.'' Others claim that new squatters, small farmers who have left the land because of the collapse of copra prices, are moving into Manila.
''Manila is my home,'' said Pasqualita, ''and I'm staying here until I have no home left.''
If the government pushes ahead with the ''last campaign,'' some observers fear serious confrontations between squatters and their supporters, and the authorities. Others, however, predict that the program will just fade away. ''Lots of programs begin like this,'' one said, ''but after the initial sound and the fury, they just peter out.''