SEOUL: ALL DRESSED UP AND RARING TO GO

SEOUL is ready. The wide waters of the Han River have been cleansed. Ribbons of concrete highways stretch across the city. Gleaming subway cars flow into clean underground stations. Modern glass-fronted skyscrapers crowd the city center. The street peddlers and their carts have been moved out of sight. Even the walls of all the automobile tunnels have been covered with white tiles. Everything is in place for this ancient city to host the XXIV Olympiad. The largest Games in Olympic history begin on Sept. 17. The city expects to receive some 13,000 athletes, 14,000 media representatives, and over a quarter of a million visitors.

Seoul has come a long way to get to this moment. The founders of the Yi Dynasty chose it as Korea's capital at the end of the 14th century. The city was a natural fortress, flanked by mountains on three sides, with the Han River to the south, flowing from east to west.

Historic Seoul remained within that basin formed by the natural barrier of the river until well into this century. The centrality of that old capital persists today in Seoul's downtown business district, still the core of the now-sprawling metropolis. Remnants of old palaces, city walls, and gates sit amid monuments of modernity.

The Seoul that is hosting these summer Olympic Games is in many ways another city, a modern city that has grown on top of and around the old Seoul. The origins of modern Seoul begin darkly, with the 40-year period of Japanese colonialism that only ended in 1945. The Japanese built up the city, creating streetcar suburbs surrounding the traditional center to house the colonialists.

Not long after the end of Japanese colonial rule, Seoul was occupied again - this time by the invading communist troops of North Korea in the early phase of the Korean civil war. During that war, almost a third of the city was turned into ruins.

When the fighting ended, Seoul became a magnet for those displaced by the war. The city swelled with squatters - refugees from the North, returning citizens, and migrants from rural areas. They filled the hillsides with shanties and makeshift dwellings, creating settlements called ``moon villages'' that persist to this day.

This flood into Seoul is the basis of the new city. Ask the average citizen of Seoul where he or she is from and the answer will invariably be another part of Korea. According to city planners, only 15 percent of the present population were born in Seoul.

Starting in the 1960s, the city began to boom, as did the rest of South Korea. ``There was great economic development through the 1970s,'' says Do Myung Jung, the director general of Olympic planning for the city government. ``But the side effect of development was the large influx of population into Seoul.''

The city burst its old bounds, spilling across to the southern bank of the Han. The Rev. Jack Trisolini, a Roman Catholic priest who first came to work in the Kuro district of southern Seoul in the late 1950s, describes the area then as still largely rural. Today, it is a dense jumble of factories and apartment blocks, with hardly an open space.

The growth of the city, says Mr. Do, brought problems with it - lack of transportation; pollution; and housing shortages. ``We have a huge amount of population in a small area,'' Do explains. All main roads flowed into and out of the old city, causing increasing logjams of traffic. The main shopping centers were there as well.

The strategy that was developed to deal with these problems, Do says, ``was to change the structure of Seoul city from one core to several cores.''

The area south of the Han has been the main recipient of this urban planning policy. About half of Seoul's 10 million residents now live there. It has become the haven of the growing and increasingly affluent middle class. They live in rows of modern apartment blocks, with carefully tended green lawns below.

The southern development has created an imbalance with the old city. The area ``has attracted a relatively wealthier sector of the population and received a disproportionate share of urban services, such as school systems and public utilities,'' Kang Hong Bin, director of South Korea's Housing Research Institute, told a recent conference on the impact of the Olympics on urban planning.

The estimated $3.1 billion in investment for the Olympic Games has played a key role in accelerating this development of Seoul. Most of that money has flowed into the southern area, where all the major new sports facilities are situated.

This process began even before the Games were awarded to Seoul by the International Olympic Committee in 1981. Talk of an Olympics in Seoul started in the early 1970s. Work on the facilities that Seoul would need in order to be chosen began in 1977 with the construction of what is now known as the Seoul Sports Complex. The 70,000-seat Olympic Stadium, whose rolling shoulders imitate the shape of a Korean vase, was completed by 1984.

The investment covered the costs of a wide variety of facilities. The sports complex includes a baseball stadium and three indoor arenas. Not far away is the Olympic Park, with five venues, including swimming, gymnastics, weight lifting, fencing, and cycling. The park contains beautiful grounds filled with massive sculptures from around the world. Next to the park is the athletes' village and the press village, a 5,700-unit housing complex that has already been sold to apartment owners for use after the Games.

The real advantage to the citizens of Seoul has been the improvements in the infrastructure associated with the Games. The airport has been expanded. An ``Olympic highway'' was constructed from the airport to the sports complexes, creating the first major artery south of the river. The subway system has been greatly extended. And there has been significant improvement in air and water quality, including a massive cleanup of the once-murky Han, where Olympic rowing events will take place.

``We have already seen a lot of changes,'' says Chyun Sang Jin, an official of the Seoul Olympic Organizing Committee. ``People say hosting of the Olympic Games will advance the hosting city at least 10 years.''

Perhaps, however, the most important change brought by the Games may be the most intangible - the consciousness of new Seoul it has created among the thousands who came from elsewhere to build it. ``Through the Olympic Games,'' Do says, ``we have integrated the population, and created a feeling for Seoul.''

Last of a four-part series. The previous articles ran Aug. 30, Aug. 31, and yesterday.