We went to St. Austell in Cornwall back in September and visited the Eden Project (as you do) and when the weather permitted to some of the villages in the surrounding area. By far the most picturesque of these is Charlestown which has been used as a setting in a number of Films.
Another village we went to was Mevagissey where I had probably the best tasting pot of mussels ever anywhere (and I’ve had some good mussels in Belgium where they know a thing or two about them). I want to imagine that they were caught locally that morning but wouldn’t be surprised if they’d been imported from somewhere else.
Despite the occasional downpour during September I can easily recommend Cornwall to anyone planning a late season break but would urge them to take waterproofs and a sat-nav.