The National Park Service turns 101 on Aug. 25, 2017. It’s also one of the 10 days this year that all National Park Service sites (more than 400 parks across the country) offer free admission to everyone. 

Other upcoming free admission days are Saturday, Sept. 30 (National Public Lands Day) and Veterans Day weekend, Nov. 11-12.

Arizona sites include the Grand Canyon, Lake Mead, Canyon de Chelly, Saguaro National Park near Tucson, Montezuma Castle in Camp Verde and many more.

Smithsonian magazine sponsors this day of free admission at participating local museums and cultural institutions nationwide. There are 20 participating museums in Arizona, including Cave Creek Museum, Pueblo Grande Museum, Desert Botanical Garden, Halle Heart Children’s Museum and Arizona History Museum. Times vary. Download and print free admission tickets in advance.  smithsonianmag.com/museumday