A federal design panel approved preliminary designs for security landscaping around the Washington Monument yesterday, but it stopped short of endorsing the National Park Service's sketches for a visitors' complex that would be partially underground.

The National Capital Planning Commission's endorsement of a series of pathways and low stone walls ringing the monument in concentric ovals is an attempt to protect the structure from bomb-carrying vehicles while preserving the aesthetic integrity of the area. The landscaping plans, submitted by the Park Service, need final approval and funding. If that comes, the paths and walls -- which would be no more than 30 inches high -- would replace the rings of concrete Jersey barriers that now surround the monument.

The Park Service also submitted designs for a partially underground visitors' center. The design would bring visitors into the existing stone lodge near 15th Street and have them proceed to an atrium-style addition in the back of the lodge, where they would undergo security checks. Stairs and elevators from the atrium would descend to a tunnel that would feature a shop, educational exhibits and a skylight with views of the monument. Visitors would walk through the tunnel to get to the monument's entrance.

Several members of the panel called the atrium addition too large, and the panel instructed the Park Service to come back with at least two alternative designs. Last year, the design panel approved the basic concept of the underground center and the addition to the lodge, and yesterday it voted to reaffirm its approval of those concepts.

Although the panel had requested that the Park Service submit preliminary designs in which the atrium is smaller than the lodge, the design considered yesterday featured an atrium roughly twice the size of the lodge. Park Service officials said they had determined that security screening should be done aboveground, not in the tunnel.

To allow for the equipment to be placed in the atrium, they said, the addition would have to exceed the size of the one-story lodge, which is about 900 square feet.

"If a design comes back, and [the atrium] is larger than the lodge or with a roofline that is higher, I won't support it," said John V. Cogbill III, chairman of the panel.

Panel members heard comments from the public during a hearing yesterday, and many speakers criticized the idea of an underground visitors' center and the design of the atrium addition. Several suggested less intrusive and less expensive alternatives to the underground visitors' center. Although Park Service planners suggested that the underground center would make the monument safer, many critics said that visitors would be at greater risk if shepherded underground.

"The monument doesn't need to be protected," said Robert Hershey, president of the D.C. Society of Professional Engineers and an opponent of the design. "What needs to be protected are the people."

Dorothy Miller, advisory neighborhood commissioner for the district that includes the monument, said the proposed atrium and graded tunnel leading to the monument would make it difficult for senior citizens and the disabled to visit.

"This all adds up to a tunnel 400 feet long with 10 landings where you could rest and contemplate how much farther you have to go, except that you will have to keep up with your [tour] group," Miller said.

Judy Scott Feldman, head of the National Coalition to Save Our Mall, said the atrium would be an eyesore and incompatible with historic structures. She said that alternatives -- such as small, secure screening areas added to the existing entrance to the monument -- would provide sufficient protection and cost much less.

Arnold Goldstein, who oversees monuments and memorials on the Mall grounds for the Park Service, said the atrium and the underground facility would not clutter the grounds, as some have suggested.

"In considering the totality of the Washington Monument grounds, you would barely even see it," Goldstein said.

In another action, the design panel approved plans to add an inscription to the Lincoln Memorial commemorating the "I Have a Dream" speech by the Rev. Martin Luther King Jr. The inscription would be placed on the steps leading to the memorial, at the spot where King delivered the speech Aug. 28, 1963.