Here's a time lapse video showing the construction of an n scale micro layout using layers of pre-cut wood and rigid foam insulation. As you can see, it's pretty tiny and yet it still looks rather stunning. Features include a tunnel, a bridge, a hillside with nice rock work, and a river, both of which were carved into the foam.
It's yet another example of how you can enjoy model trains without taking up too much space!
Check out some of the other videos on the Steve's Trains YouTube channel. Enjoy!