Each year, during National Park Week  you can get into any of the 397 National Parks absolutely free. National Park Week is April 21-29 this year.
While many parks are free, not all of them are so this week is a fantastic time to see any park you want without wondering if you have to pay. In addition to free admission, there are special events and discounts at some location so look up your local parks to see what may be available.
The week starts with Volunteer Day, on the 21st, where you can pitch in  to help a local park near you.
Lastly, the week ends with National Junior Ranger Day on the 28th and it particular fun if you have kids since they have special events, including being sworn in as a Junior Ranger , just for the little ones.
(Photo: pagedooley )