Millions of people visit our national parks every year, and the U.S. National Park Service has some easy tips for how you can help preserve them when you visit. While an unusual rock, gorgeous flower, starfish or even shed antlers found in the woods may seem like the perfect souvenir to bring home -- don’t. Not only is it illegal, but imagine if every person who visited the park took just one thing: It would significantly degrade the park and impact wild animals. Instead of driving to a park and fighting for a parking space, research if commuter buses exist that can drive you to and from the park. Less traffic, less hassle -- and you’ll have more time to enjoy your visit to the park.