After the lights project, I went on to install a backdrop on the layout. Here are a couple of pictures about that. Click any of the pictures to view them in a bigger size.

The backdrop is standard Faller backdrop, model "Neuschwanstein". The backdrop is installed in a separate frame, and it is standing on its own feet. So I can put it away anytime I need to work on the backside of the layout. In addition to the main piece, I also made a smaller piece for the corner. This is how they look like, when placed behind the layout.
Main view from the "East".  Main view from the "West".
The smaller piece connects to the main piece almost seemlessly in the corner. Station view.
Farmer's house in the forest. And view from the ground level.