Depends how high it is. You will def need Iron beams will be needed for support but you might also plant some pine trees (so if you haven't gotten to the swamp I would put this on the back burner). Trees work great as anchor points that are just like building on the ground. I would start at the bottom and slowly work your way up to that height adding structural items as needed. You can cover stone with wood (use iron gates to support the stone) so that it all looks wood too. Good luck = ]