All national parks open for free this weekend

If you want to get outside and enjoy some fresh air, this weekend may be the perfect time to do so.

This Saturday, you can get into all U.S. national parks for free.

The entrance fees are being waived to kick off National Park Week.

Things like camping, transportation and special tours will still cost you, but admission to the parks will be free.

More than 400 national parks will take part.