pickupimage and wikimedia.
It was marked as Public Domain or CC0 and is free to use. To verify, go to the source and check the information there.
This image was acquired from
Keywords from Image Description:
... Great Wall Badaling. en Great Wall Badaling own Hermann Luyken other versions heading cczero Uploaded with Great Wall of China at Badaling
Page 2017 Free-images.com. All images are Public Domain