We are currently staying at our beach-house cabin for a few more nights. I would like to do a craft with my son tomorrow while my husband does a few fix-up projects around here. I was thinking we could do something he could leave here at the cabin to see each year when we come back. Any good ideas? We are going to be near a craft store tomorrow morning, so I can pick supplies up. I don't mind if it's messy, as we have a big grassy area, or cement area, or deck to do it on. Plus he will be going swimming after, so any mess will get cleaned off in the ocean. We also have access to sand, shells, etc. What would be easy, and cool to look at for years to come?