MEADOWSIDE NATURE CENTER -- 5100 Meadowside Lane, Rockville. 924-4141.

Nature is nice as long as they keep it outdoors. At Meadowside Nature Center in Rockville, though, nature is air-conditioned, bug-free and without a trace or posion ivy.

There's something to be said for the painless dose of things natural at Meadowside's "curiosity corner," where kids look at scaly skins and butterfly wings under a microscope, touch all manner of furs and peer at live animals, notably snakes, behind glass. Nature movies and a planetarium also beam wide-world information to suburbanized youngsters.

But the key exhibit, "Legacy of the Land," is a pricey project with as many critics as fans. In a large cool room, tour groups of 15 or fewer get a feel for the land, once removed. Visitors see Maryland tobacco plants and barn animals, walk through mountainside, riverside and meadow mock-ups in the space of a few yards, explore an "earthen" tunnel and crawl through a simulated cave to observe stuffed animals in their ersatz natural habitats.

Children may love it, but some naturalists are not enthusiastic.

"It breaks my heart," says park naturalist Denise Gibbs. "Groups go through the tour and never take a nature hike, never see the pond or lake or pioneer farmstead that are here, too. People miss them because they can't see them from the parking lot."

What they can see are stuffed and artfully arranged river ott, strokable beaver, scarlet tanager, male red-breasted grosbeak, flying squirrel (there's a live one in "curiosity corner"), wood duck, red and gray squirrels, a cottontail rabbit, ring-neck pheasant, muskrat, wild turkey, raccon, woodthrush and great fox. Then there are the living celebrities: snapping turtle, large-mouth bass, bluegills and crappie visible through underwater portholes as well as from dry land.

Still, "Legacy" is an artistic achievement that probably serves as a primary brush with wilderness for the Beltway-bound. On a recent Saturday, a group of four kids and their parents were delighted by the show's authenticity. There were special raves for the cave: It's a carpeted, grit-free monument to Huck Finn in a fiberglass age.

"Someday we'll take you to a real cave," Jeff Schmitt's mother promised the 5 1/2-year-old as he scampered after tour guide Mark Jirgal. An intern from the University of Maryland studying conservation resourse management, Jirgal turned a flashlight on stalactites (hanging like ts from the ceiling), stalagmits (up from the floor like ms ) and the stuffed bat among the cave's life-like roots and clay.

"I wish we could see some water dripping down," Jeff sighed when told that's how the stalacties and stalagmites are formed. In fact, when the cave is complete, another section will show water dripping from above plus more delicate rock formations -- safely out of visitors' reach.

Dan Rhymer, senior exhibits specialist at the Maryland-National Capital Park and Planning Commission, who designed "Legacy," says it took $20,000 and eight years to build. Nearly a hundred artists and consultants from the Department of the Interior, National Aquarium, National Forest Service and other state and federal agencies contributed expertise.

"We wanted to avoid the diorama approach that has viewers on the outside looking in," Rhymer says. "Instead you walk inside the exhibit. We have live fish and road-killed animals and we're constantly adding new one."

This is no plastic show: It took 10 tons of rock from Washington County to build the wall around the exhibit's "mountainside." The fish are real, the plants and trees need care and feeding and it takes lots of maintenance to keep the mouse and insect populations down, he says. Rhymer boasts that the exhibit has no signs or labels, but tells its own story. And it's become a model for other nature centers.

"It's not intended to replace nature trails. But people do come who don't want to walk a mile or two on a trail," Rhymer notes.

That's go to be better than staying at home to watch "Those Amazing Animals."