After nearly 50 years of operation, a neighborhood museum in the Palisades with an eclectic collection of toys and artifacts donated by local embassies has been handed an ultimatum by the National Park Service: either change or move out.

The Children's Museum, which is used primarily to introduce neighborhood children to other cultures, is housed in the 126-year-old one-room Conduit Road schoolhouse on MacArthur Boulevard on land that is part of Rock Creek Park.

Established and managed by volunteers, the collection consists of items donated by European, Asian, African and South American embassies. It is set up with antique desks as a 19th-century schoolhouse, but its bookshelves are crammed with musical instruments, dolls, trinkets, maps and books from Japan, Germany, France, England and other countries.

The biggest attraction is the brass plate exhibit, which attracts children from around the region to make rubbings with wax crayons of medieval kings, queens and knights. The museum charges $1.50 to $4 for the activity and nets about $6,000 a year toward operating costs, a museum official said.

Organizers also offer puppet shows and other activities, often with an international focus.

And that's the problem, say Park Service officials, who have given the museum volunteers until Sept. 15 to change the focus or face eviction. Parks officials said they think a museum in the old schoolhouse should focus either on American history or environmental issues more in keeping with the park's mission.

"While it is interesting, it doesn't have anything to do with what the National Park Service is about," Rock Creek Park Superintendent Rolland Swain said. "Our purpose is not to furnish structures for people to carry out activities that could be carried out elsewhere."

Park Service officials said all they need by Sept. 15 is an indication that museum organizers agree to change their focus and will develop a plan by the end of the year. But organizers said if they are to continue volunteering their time, they want to do things their way. Several hundred supporters have signed a petition asking the Park Service to reconsider.

"They want a radical change," said Diane Bessette-Stillions, a Palisades resident who volunteered to be on the board of directors in June. "All the artifacts that make it special we're being asked to get rid of."

The museum was established in 1941 by Matilda Young. Few now connected with the museum seem to know much about her, but the museum originally was housed in the Villa Rosa mansion on Massachusetts Avenue NW.

In 1944, that property was sold to a private developer, leaving the museum homeless. It moved from place to place -- even to an old trailer coach that functioned as a traveling museum -- before it finally ended up at the schoolhouse in 1966.

At the time, its founder signed a special-use agreement with the Park Service to run the school as an international children's library.

The operation gradually expanded, while the conditions for Park Service permits tightened. Officials now say the museum no longer falls within permit guidelines. They also say it has become less organized since founder Young died last year.

Museum officials said they plan to ask the city to take over the site or to try to take it over themselves.

Council member Jim Nathanson (D-Ward 3) said the city has no funds to take it over. "It would be a shame to lose it. It has been a valuable tool and a learning experience for the youngsters," he said. "What I'm hoping is that the Park Service will give the community time to work this thing out."