KOREA is known as the ``Land of Morning Calm.'' But when the sun rises over the broad Han River -- and the rolling valley where Seoul sits bathed in morning mist -- it rises over a city vibrant with activity. Seoul's nine-lane avenues are frequently gridlocked. Aggressive bus drivers rival the most notorious in Rome. Screaming mopeds zip onto sidewalks and into alleys where hordes of international shoppers take advantage of some of the best bargains in Asia.
``My hometown has become a tangled colossus,'' laments Seoul-born Lee Sang Kyung. ``There is too much of everything -- pollution, people, politics.''
``Twenty years ago, I left behind a peasant metropolis,'' adds Han Kim, a professor at the University of Michigan. ``I went back this year and thought I was in Europe.''
He might have thought he was in Europe this past Sunday, too, when a terrorist bomb went off outside Seoul's Kimpo Airport. The city, proud host to the Asian Games opening Saturday and to the 1988 Olympics, has been trying to prevent precisely such attacks. South Korean officials promptly suggested North Korean involvement.
Meanwhile, the traffic jams here show that in South Korea, all roads -- social, economic, and political -- lead to Seoul. Growing tenfold in population since World War II, doubling in the last decade, this capital of one of Asia's so-called ``miracle'' economies has become the world's fifth-largest city.
``In Korea now there is only Seoul,'' says Professor Kim, who has watched the phenomenal growth of the capital through annual visits spanning 20 years. ``Restaurants, nightclubs, shopping, cultural events -- the other cities don't even compare.''
The news that comes out of South Korea in the international press tells of political unrest. In Seoul alone, there have been 557 demonstrations this year against the government of President Chun Doo Hwan. Yesterday, about 2,000 students clashed with riot police in protest against the costly Asian Games.
But behind the headlines is a story less told: of how Seoul rose from the devastation of the Korean war (1950-53) to become a cultural and commercial giant. Through scrupulously orchestrated planning, South Korea has multiplied its gross national product 38-fold since 1961, averaging 8 percent growth for 20 years. (Since 1984, there has been a slowdown in exports -- which had soared from $119 million in 1964 to $32 billion in 1985 -- but the impact has been eased this year with the help of low oil prices.)
In the capital, a new middle class has emerged. And with its emergence, the face of the city -- housing, office space, parks, and cultural centers -- has been transformed. Now, with the Asian Games and the Olympics, Seoul is capping three decades of growth with a final housecleaning. The goal is to put the best foot forward for international visitors and the news media.
Kim Zohng Chill, acting president of the Korean National Tourism Corporation, points from the eighth-floor window of his downtown office, enumerating five years' worth of city and national government projects that are 75 percent completed.
Next to the slow-moving Han River are huge piles of sand. They have been dredged up in an antipollution project that has changed the river from a virtual city sewer to a recreational waterway (``Fishable now, swimmable by 1987,'' Mr. Kim says). River-polluting factories have been relocated, and the river has been lined with hundreds of sports parks and picnic areas.
Around one bend in the river is a 40 percent-completed ``Seoul Grand Park,'' an entertainment complex three times the size of Disneyland. An art museum recently opened in the park.
Housing is in such demand, Kim says, that a 13,000-unit complex built for the visiting athletes was snatched up by private investors, and organizers had to build another. Buildings more than 11 stories high are required by the city to provide public art displays, inside and out, and are to be surrounded by trees and shrubs.
Across town, Sangjin Chyun, a member of the Seoul Olympic Organizing Committee, expounds on the many uses that will be made of the Olympic Stadium and other arenas and gymnasiums by the people of Seoul far into the future. ``All this is really the result of 30 years' planning,'' he says of the sports complex situated about half an hour from downtown.
In a just-completed state-of-the-art subway (the world's seventh longest), tourists, sports fans, and Seoul residents can zip across town quickly. Still under construction are an Equestrian Park, a regatta course, and a yachting center.
``Seoul's rising standard of living, developing economy, and accelerating social environment demanded we build all this -- even if we never held the Olympics here,'' Mr. Chyun says.
But he and others also see another valuable legacy from being host to the coming extravaganzas -- at least a temporary change in government attitudes.
The government has dropped some restrictions, such as a mandatory curfew in effect since World War II and certain dress codes for students. The curfew had ordered all South Koreans off the streets from midnight to 4 a.m. Uniforms for students were a way of life.
But even though the service industry is gearing up -- with campaigns such as teaching taxi drivers to speak the basics in many languages -- there is still an atmosphere of caution.
``I took 17 students on a one-week tour of [South] Korea recently,'' says Prof. Sugwon Kang, a Korea specialist at Hartwick College in Oneonta, N.Y. ``And though I didn't tell them -- they never noticed -- we'd been shadowed by [intelligence] agents every moment from Seoul to Cheju Island and back.''
Indeed, though shopkeepers, drivers, and hoteliers are friendly and courteous, this writer noticed what may have been plainclothes agents on three separate occasions in nine days. One man leaped out to admonish me not to take pictures in the subway when I tried to photograph the subway art. Six or seven appeared in the alley after a I called on opposition leader Kim Dae Jung. Others were pointed out on street corners by American residents we met during our visit.
Part of the government's concern is over any contact South Korean university students might have with international visitors.
``The reason you read so much about student activism -- and that the government is so concerned about stopping it -- is that students have played a major part in bringing down the last three regimes,'' says H. B. Suh, an official at Hyundai, a giant South Korean conglomerate.
Also disconcerting to the foreign visitor may be the country's monthly half-hour civil-defense ritual. On the 15th of each month, sirens sound and agents appear to whisk everyone off the streets and out of hotel lobbies and into basements. For 15 years, the government has repeated the exercise, as an emergency evacuation procedure in anticipation of an attack from the North.
For the most part, though, the Olympics will unveil a Seoul most of the world has never seen -- and observers here and overseas see this as a public-relations victory.