Cornwall has attractions to suit most people, one that suits a wide range of people, is the Eden Project.
The site consists of two large biomes situated at the bottom of a disused quarry, the whole site including the outside gardens, covers 13 hectares. The Rainforest and Mediterranean biomes are basically climate controlled massive greenhouses. Featuring plants and features of their relative areas, they are interesting to even the least of green fingered people. It is hard to explain the size and range of things to do at Eden, in the winter there is ice skating, in the summer they have live music. In 2019, Kylie Minogue is due to appear. In the past they have had acts like Lily Allen, Mark Ronson, Motorhead and the Stranglers, to name a few.
If you want to learn more, look at their website – https://www.edenproject.com/
When you are there, wandering around, you may even get a glimpse of out boat, Stingray, in one of the project films they are showing.