It is a very wet day in Borrowdale and the valley is dripping with nature as well as torrential rain. As we walk through the temperate rainforest looking for rare lichens as part of the declaration of Borrowdale as a national nature reserve (NNR), cuckoos and green woodpeckers sing through the rain. The declaration is the culmination of a lot of work for the Natural England and National Trust staff who have been involved in the designation, a lifetime’s work for some of the tenant farmers and environmental experts on the walk, and generations of previous inhabitants who worked the woods sustainably. The woods in the Lake District have been used as a resource for fodder, fuel and charcoal for hundreds of years. Temperate rainforests used to cover a belt of the UK, but now only 1% of land cover is this rare and precious habitat. Part of the plan in recognising this as an NNR is not only to protect it but to expand the woodland into other areas, largely by natural colonisation, so that nature can spill out from this valley into others. The future will be even more amazing, protected for everyone for ever by the National Trust. It is hard to chivvy everyone along the walk through the woods as people keep being distracted by liverworts, mosses and lichens that are globally very rare. I sit on a mossy knoll and talk to John Hoosan, an NT nature conservation adviser, who teaches me the names of some of the ferns in the woods while we wait for the others to catch up. He tells me that the mosses and ferns need a combination of clean air, an oceanic climate and long-lived woodlands to thrive – and this is the Seathwaite Valley, the wettest place in England with up to 3,500mm (140 inches) of rainfall a year. After the walk we make our way to an inviting space at Seatoller Farm for tea and cake. Tenant farmers Dan and Ruby Simpson provide the refreshments for everyone, in a barn that they renovated beautifully for their wedding six years ago. They are the latest in a long line of Borrowdale residents who have cared for this precious landscape.