It won't cost a cent to enter into any of the country's national parks starting Saturday.
Park fees are waived as the first day of National Park Week kicks off.
"On six days in 2021, all National Park Service sites that charge an entrance fee will offer free admission to everyone," the National Park Service said.
There will be a charge for camping, transportation, activities and tours.
The celebration runs through next Sunday, April 25.
"National parks are America's best idea, and there are more than 400 parks available to everyone, every day," the National Park Service said. "The fee-free days provide a great opportunity to visit a new place or an old favorite, especially one of the national parks that normally charge an entrance fee. The others are free all the time."
National parks across the country will also host a variety of special programs, events and digital experiences.