certainly have no local knowledge of those places, but my first reaction is to contact a store there, or a hotel, or who knows what, even the police station or something and ask if you could leave your case with them for a week. If its an establishment that you are actually spending money at, that tends to be better imo.
I'm sure you could find someone to hold it for you, just have to get some personal contact with people, be friendly and see what happens.