Unfortunately, as an AI language model, I do not have the capability to browse the internet to gather information. However, I can provide you with a general summary about parks in Illinois to help you out.

Illinois is home to a variety of parks that offer visitors a chance to experience the beauty of nature. Some of the popular parks include Starved Rock State Park, Matthiessen State Park, and Shawnee National Forest. Visitors can enjoy hiking, camping, fishing, and other outdoor activities in these parks.

Starved Rock State Park is known for its scenic canyons and waterfalls. Matthiessen State Park features unique rock formations and beautiful forested areas. Shawnee National Forest is the perfect place for outdoor enthusiasts, with its 280,000 acres of forest, rivers, and trails.

Illinois is also home to several historic parks, such as Lincoln Home National Historic Site, which is the former home of President Abraham Lincoln, and the Chicago Riverwalk, which offers stunning views of the city's architecture.

The best time to visit parks in Illinois depends on the season and the activities that visitors want to enjoy. Spring and fall are great times to visit for hiking and outdoor activities, while summer is perfect for camping and fishing.

Overall, Illinois offers a wide range of parks and outdoor recreation opportunities for visitors of all ages and interests.