I have a collection of pictures which are other’s work released under a free license. You can download them from here.
All the photos attached below are taken by me. I have released all the photos under Creative Commons Attribution-Share Alike 4.0 International License. Under this license, you are free to use, share(even commercial sharing is allowed), modify for any purpose but you are required to give attribution to me. All the derivative works must also be released under the same license. This requirement gives freedom to all the users of the photo.