Happy Easter and a ravine!

I hope you're all enjoying the day. The weather here has been far too bleak to do anything outdoorsy, so I have been working on things. I have pinned and glued foam to walls, partly dug out a hillside pathway, glued windows into a mosque, and glued a plastic demi-egg shape onto a scrap of base. Today, have a gander at the ravine/pathway. My initial plan is to make three 2' (60cm) lengths  (6"/15cm deep, 5"/12.5cm tall) of ravine, one with a pathway to the top, and the other two just steep hillsides. This will in time be added to.

So I cut bits of MDF to form the back and sides, bits of timber to form supports for them, and help to ensure a semblance of right angles. I glued these in place (Fig. e1), weighted them with some spare lumps of metal, (Fig. e2) and left them to dry. Once they were secure, I cut up a spot of my old mattress foam, and glued it in place (Fig. e3). Once dry I began carving and plucking chunks from it until a semblance of a pathway began to appear. I'd like it to seem feasible for some vehicles to traverse the pathway, so I will be smoothing it further. I don't want heavy tanks trundling up the hill, mind, so I aim to keep it about 3" wide.