Washington is a city that prefers its public architecture to be straightforward and uncomplicated. Nowhere is this more true than on the National Mall, where museums and monuments are laid out and built in strict, obvious geometry. The imposing cylinder of the Hirshhorn, the broad rectangle of the Air and Space Museum and the sharpened triangles of the National Gallery's East Wing all draw attention to themselves through clear lines and bold but orderly forms.

The shape of things, however, is soon to change.

This fall, the National Museum of the American Indian begins construction just southwest of the Capitol building, on the Mall's final parcel of buildable land. The NMAI, when completed in 2002, won't remind you of any other nearby building, not even slightly. Unlike its neighbors, the NMAI aims to echo, and even mimic, the subtlety and unpredictability of nature.

The exterior, to be built of rough-hewn limestone, is designed in overlapping levels, the walls of each level curved differently from the next. The strong image is of an object carved out by winds, by sun, by water; and, indeed, the drawings and models for the project recall the cliff dwellings of southwestern American Indians. The symbol here is not of humankind imposing order on the land; rather, this building echoes a powerful American Indian belief, that nature can never be fully controlled.

Symbolism is one thing, though, practical use another. A museum design, however evocative, still exists as a shell for the artifacts displayed within, and this is the other half of the NMAI's story.

The museum has been part of the Smithsonian since 1989, and since 1994 its displays have been housed in the George Gustave Heye Center in New York City, near Battery Park. The museum's permanent collection, 800,000 pieces strong, resides inside a giant warehouse in the Bronx, and the next step, already begun, is to bring these items to the Washington area.

It is an exhaustive, meticulous process. More than 30,000 bar-coded items -- including clothing, pottery, weapons, utensils and canoes -- have been transferred to the brand-new Cultural Resources Center in Suitland, where each is inspected, digitally photographed and stored. This move, which will take at least five years to complete, represents one of the largest and most technologically ambitious museum collection transfers in U.S. history.

Though the Smithsonian's NMAI building is six months from first construction and at least three years from completion, the museum staff in Washington is already on the job full time. The Smithsonian's slate of Heritage Month activities is large and varied, and includes films, lectures and a selection of interactive children's programs, as well as the ongoing exhibit "George Catlin's Indian Gallery" at the National Museum of American Art.

And there's always the site itself, that triangle of land next to the Air and Space Museum. Though it might not yet hold museum displays, many in the American Indian community already consider it sacred land. Blessed by song, speech and sprinkled tobacco at September's groundbreaking, this final plot of unbuilt earth in the nation's symbolic center is worth one more look, before the bulldozers roll and the undulating limestone walls of the NMAI begin to rise.