WASHINGTON (AP) _ The observation deck atop the Washington Monument reopens to visitors Monday behind a scaffolding grid for workers cleaning and repairing the monument's marble walls.

Its interior has been closed since Oct. 5 to allow workmen unhindered time to erect the metal and fabric web now enclosing the outside surfaces of the 555 foot obelisk.

Meanwhile, work is nearing completion on the monument's first-ever interpretative center, which uses sections of the scaffolding to frame display panels focused on George Washington's life.

When the temporary center opens next weekend, visitors can pose with a replica of the monument's aluminum-capped tip, listen to recordings of workmen reporting the progress of the repair work and view a televised kaleidoscope of images of demonstrations and ceremonies at the monument's base.

A central chamber reproduces the observation deck, down to the water and rust stains on its marble-sided walls. Visitors can see the topside views via video screens without ever venturing into the monument itself. The $2 million center was financed by a donation to the National Park Foundation by Discovery Communications Inc., parent company of Discovery Channel.

All repair work is to be completed and the scaffolding removed by the middle of 2000. The visitor center will close in September of that year, although the National Park Service eventually hopes to replace it with a permanent facility.