Simon looks at the impact of humans on England’s biggest and most popular national park. He goes wild swimming in the crystal clear lake of Buttermere, before taking a look at the less fortunate Derwent Water, one of the many lakes now clogged with the invasive New Zealand pygmyweed. He also visits England's highest peak, Scafell Pike, where he discovers that the sheer footfall of so many yearly visitors is damaging the mountain and stretching rescue volunteers thin.

Outside the Lakes, Simon talks to experts who are trying to understand flooding in Carlisle, which they believe is caused by a mixture of climate change and the upstream flooding of artificially straightened rivers. He finds out about a project to restore the original boundaries of such rivers, which can also help to return wetlands like Foulshaw Moss to their former glory. Show less