The northern Lisbon suburb of Benfica is a monument to the success of modern Portugal, a concrete forest of high-rise buildings built with the sweat of new arrivals.
These days, the migrant workers are usually from Africa. Faces masked to shield them from fumes, hundreds of Angolan and Liberian men move back and forth across girders high above the streets, dumping and spreading freshly mixed concrete. Many are part of a tide of more than 80,000 people from around the world who have flooded this tiny nation in recent years, lured by an explosion of new jobs and the promise of a better life.
Not since the Moors swept northward from Africa in the 8th and 9th centuries has Portugal seen such a large wave of foreigners, experts here say.
But the influx also comes as Portugal is formally preparing to meet its obligations on immigration as part of the European Union. The EU's Schengen Accord does away with internal border checks among nine European partners. They are concerned about immigrants who will be crossing over from Portugal.
The phenomenon has come about, in large part, because of dramatic changes in recent years.
From 1932 to 1968, the country was a virtual dictatorship under Premier Antnio de Oliveira Salazar, followed by a military coup in 1974. Military leaders gradually relaxed control, however, and civilian government resumed in 1982.
Portugal is still Western Europe's poorest country, with a per capita income of $11,000, well below that of fellow EU neighbors such as Germany and Italy. But by pulling free of its authoritarian past, Portugal has thrust itself into a position of unprecedented growth and prosperity, to become a full-fledged member of the EU.
Portugal "has become a mecca, a popular destination for people from many countries around the world, many of them former colonies where poor Portuguese flocked to until only recently," says Alcestina Tolentino, a representative of the Lisbon-based Association of Cape Verdeans, an immigrant group.
Migrants include immigrants from Mozambique, Brazil, East Timor, Angola, and Cape Verde. Others are arriving from Macau, Portugal's last remaining colony, which will revert to China in 1999. Many of the migrants have an open door into Portugal because they hold Portuguese passports or can exercise special residency privileges that go back to the colonial era.
"It's a comfortable place to be," says Brazilian Jos Rocha, working at a food kiosk along Lisbon's waterfront. "Here, I can speak my native [Portuguese] language and enjoy my own culture and food, and I can work at a job that pays a decent wage."
PORTUGAL'S diversification has so far evolved with little of the racial strife visible in many other European nations. But for Lisbon the situation is getting more complicated. Required to align its immigration policies with those of increasingly anti-immigrant EU partners, the Portuguese government is having to make some difficult decisions.
Recently it announced it would begin arresting employers found to be using illegal workers, and the congress is considering tightening residency requirements for non-EU nationals.
Before doing so, though, it organized an amnesty program that allowed 35,000 Portuguese-speaking illegal immigrants - about 6 out of 7 of those up for review - to remain legally in the country.
The moves illustrate a fundamental paradox for Portugal: At a time when it seeks to move further into Europe, it feels a growing obligation to lend a hand to former colonies.
"Portugal is being pulled away from what has been its historical focus," Ms. Tolentino says. "Now it faces the tricky prospect of trying to somehow appease these two essentially conflicting constituencies."