The University of Illinois calls its arboretum a living laboratory because academic experts conduct research on plant growth on these 57 acres. But it's also a delightful place to stroll and take in the beauty of nature. The centerpiece is the Miles C. Hartley Selections Gardens, where hundreds of flowering plants, such as zinnias and marigolds (all of them clearly identified with little signs), grow between concrete or stone walking paths, forming artistic geometric patterns when viewed from a distance. The path leading from the main parking lot into the Hartley gardens is pretty, too, flanked on either side by blossoms and towering elephant's ear. The Idea Garden is where the Master Gardeners of the Champaign County Extension Unit experiment with borders, ornamentals and vegetables. And the Noel Welcome Garden offers some shelter with pergola, benches and crabapple hedges. Around these main gardens, the rolling grounds look something like a golf course, with trees, ponds and expanses of grass. The Japan House is surrounded by traditional Japanese tea gardens. The free arboretum is open every day from sunrise until sunset.