The major permanent exhibit, "A Walk Through Time in Georgia," uses the state as a microcosm to tell the story of the earth's development through time and the chronology of life upon it. Eighteen galleries here re-create landform regions from the rolling pine-forested foothills of the Piedmont Plateau to the mossy Okefenokee Swamp, from the Cumberland Plateau (where you can walk through a typical "limestone cavern") to the marshy Coast and Barrier Islands. Exhibits are enhanced by creative films and videos, informational audiophones, interactive computers, sound effects, and old-fashioned field guides--not to mention more than 1,500 fabricated plants and mounted specimens of birds and animals. Visitors travel back 15 billion years--to experience the origins of the universe (the Big Bang) and the formation of galaxies and solar systems--and into the future to consider the fate of our planet. The highlight of it all, though, is the gallery of seven life-size dinosaurs and three massive murals of three prehistoric periods.

Another major permanent installation, "Spectrum of the Senses," comprises 51 participatory displays that tease the eyes and ears into understanding the concepts of light and sound. Here you can step into a life-size kaleidoscope, play with perspective, gaze into infinity, see physical evidence of sound waves, and mix colors on a computer. In Fantasy Forest, a colorful play area designed for preschoolers (ages 3 to 5), kids become bees and pollinate flowers, climb a treehouse, walk through a swamp, and play at being farmers. The state-shaped Georgia Adventure is a similar discovery room for ages 6 to 10.

If it's a weekend, see if there are any programs going on at the Harris Naturalist Center, a cluster of science laboratories where visitors often get to examine items under an electron microscope.

While you're here, be sure to catch a stunning IMAX film (buy tickets as soon as you enter the museum; they sometimes sell out). The immense IMAX screen--five stories high and 72 feet wide--puts you right in the middle of all the action.

Other museum attractions include a wetlands exhibit, a Caribbean coral reef aquarium, the Star Gallery (where 542 fiber-optic stars create a twinkling evening sky), the World of Shells, and the McClatchey Collection of jewelry and textiles from the old Silk Road countries. A museum store is stocked with entertaining and educational gifts and books, and there's a restaurant with arched windows overlooking Fernbank Forest, as well as outdoor patio seating.