If you plan this coming weekend to visit one of the 147 units of the National Park System that charge entrance fees, you can spend your money some other way. This weekend will be entrance-fee-free across the park system.

The freebie is the National Park Service's enticement to get you to start your summer with a park visit.

“National parks offer visitors great places to exercise their bodies and their minds- or just relax with family or friends,” said Park Service Director Jon Jarvis. “Check out the birding caravan at Acadia in Maine or be part of the 50th anniversary celebration at Bent’s Old Fort in Colorado. Whatever your interests come on out this weekend and experience the best places that America has at the best price you’ll find - free!”

National Trails Day on June 5 is an opportune time to hike a portion of the 17,000 miles of trail located in national parks. Additionally, the National Trails System, which is managed by the Park Service, encompasses more than 50,000 miles of historic and scenic trails of national importance, such as the Appalachian National Scenic Trail and the Selma to Montgomery National Historic Trail and more than 1,000 national recreation trails of local or regional significance.

Park entrance fees will also be waived on August 14 and 15, September 25, and November 11, 2010. Fees for activities such as camping, reservations, tours, or concessions, however, will remain intact.