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:
Duomo di Siena Campanile top. Siena's Cathedral Doms von Siena own heading NNW Cathedral Siena Exterior Quality Images by Taken with Nikon D
Page 2017 Free-images.com. All images are Public Domain