This is a photo of level 3, 2 and 1.  The holes are cut out in case a train derails.  The next stage is to make a lift-up scenery with one track at the back and scenery at the front.

This is the same view which includes an incline.  At the far end the track is at the front and the lifting scenery is to be at the back. This creates a gentle curve at this level.