Guardian: We’re in a corner of Cornwall that has some of the most spectacular beaches, local food and heritage in the county, but all my young children want to do is look at the “big machine that eats trees”, otherwise known as the woodchip boiler. I wish I’d never mentioned it. The Trelowarren estate on the Lizard peninsula has been welcoming guests since, well, no one’s exactly sure – the residing family, the Vyvyans, have been there for 600 years and their 1,000-acre property is …