In the early sixth century, the king's gold crown ornaments were built to last. Several examples are on view at the Museum of Natural History, so delicately crafted that the tine droplets vibrate as you walk near the glass case. Nearby is the spectacular "Thousand Cranes" vase, largest existing masterpiece of inlaid celadon, the pale-green glazed ceramic style in vogue in the mid-12th century. And hanging in quieter carpeted rooms, stunning silk scrolls by the Confucian scholar-painters of the Yi Dynasty are long on bamboo: strong but bending with the wind.

"5,000 Years of Korean Art," the most comprehensive collection of Korean art objects to be shown in this country, graces the museum through September, while the museum's Learning Center offers a sampler of "Contemporary Korean-American Arts" and lectures, films, tours, dance and art demonstrations. Across the Mall, the Freer has arranged a modest roomful of its Korean collection to complement the main show, with a 14th-century Buddhist silk painting as the centerpiece.

At the National History museum's new Thomas Mellon Evans Gallery, crowns and jewelry recovered from fifth- and sixth-century royal tombs cap a dazzling collection of 30 gold works. Nearly a hundred ceramic pieces (from a 5,000-year-old neolithic vessel to the green celadons of the Koryo Dynasty), more than a score of Buddhist sculptures and half a hundred beautiful and symbolic paintings round out the show, aimed at familiarizing Americans with Korean arts. Texts offer snippets of Korean history and culture, with emphasis on the Buddhist influences in ritual vessels, urns and icons. As a geographic bridge between the Asian mainland and Japan, Korea adopted a range of artistic methods and styles, specifically borrowing Chinese themes in paintings. But the full and more natural figures, as in the famous "Seated Buddha of the Future," and inlaid pottery techniques are distinctly Korean innovations.

In conjunction with the show, Korean weekend activities begin Friday through Sunday with Madame Hee-jin Kim, national "Living Cultural Treasure" of Korea, demonstrating the making of ornamental silk knots and cords at 11 and 2 on the museum's third floor.

On following weekends, there'll be more demonstrations by Madame Kim and Shaman ritual and masked dances next weekend, as well as daily brush painting, calligraphy, woodworking and pottery demonstrations; in mid-August Korean court and folk dances, the Korean Broadcasting Dance Troupe, pottery, brush painting, calligraphy and woodworking demonstrations, and Korean martial arts at 1 in the Sculpture Garden; and in September, performances of traditional Korean court and folk dances.

5,000 YEARS OF KOREAN ART -- At the Museum of Natural History through September 30.; KOREAN ART -- At the Freer Gallery of Art through September 15. Daily, 10 to 5:30.