You must have found at least one in your caching career. The useless container that doesn't keep out water. The recycled take-away container or the cheap plastic tub carefully disguised by the big rock which has smashed the flimsy plastic.
Or the reused icecream tub that doesn't seal too well, or the metal tin which rusts so that it becomes more and more difficult to open. And then the owner can't even decide what size to list it as...
Cache placed with the kind permission of the rangers of Almondell & Calderwood Country Park.