I'm looking for a holiday of up to a week in late September, somewhere where I can get a bit of warmth before the winter. Because I'll be by myself I know I'll get bored with just sitting on a beach, so would like to be somewhere where there are interesting things to do/see, as well as well as swim. Places like Split/Dubrovnik or Valencia/Barcelona - but I've been to all of those. Any other ideas? It probably needs to be within Europe, due to budget/time, and the swimming doesn't have to be in the sea.