Creating a nest from zero and fixing it into a tree is such a great experience! It leads you into research, then into finding the right materials, then it sharpens your creativity, because the assembly is not an easy operation.
Climbing a tree with proper safety means is not such an easy thing. A skilled friend of mine, rock climber, helped me with all the equipment and the technique. After carrying a 20 kg backpack full of mountaineering devices on the top of the quarry, we found the right spot to place the nest (some solid branches at the height of approx. 10 m).
Three hours later the nest was fixed up in the spruce tree, waiting for the hawks to settle.
We will see if this is going to happen next year, but I believe that creating new nesting spots for the birds of prey definitely represents a way to increase biodiversity.