Every time we go to the beach we collect shells. I started putting the shells in little glass jars and then labeling the bottom with the date we went.
This gives us a little collection of all the times we have gone. We even brought some back from the creek the other day. The shells are mostly black or gray and closed. The ones you find at the beach are usually pulled apart already.
I love our little collection. I have them on my kitchen windowsill. Whenever I am doing the dishes I think back to the little trips we have taken. Hopefully we will add some more jars this summer as we visit the beach and other places.