You've got to admire Dulwich Picture Gallery's dedication. Its intrepid curators have spent years travelling to the Norwegian wilderness to document the work of Nikolai Astrup and Astruptunet, the collection of buildings – huts, really – that he called home for the last 14 years of his life. Astrup isn't the most famous figure, much overshadowed by his contemporary Edvard Munch. But, when you see Astrup’s enchanting pictures of fjords, mountains, meadows of marsh marigolds and midsummer-night bonfires you’ll immediately fall for their subtle blend of mysticism, sex, longing and anguish. Astrup dedicated himself to a handful of motifs, such as huts, flowers, mountains and fjords, painting them at different times of the day and year. But he went further than most by stage-managing the natural world, clearing and planting trees and building paths to turn his patch of land not only into a source of inspiration and a beautiful artwork in its own right. Fortunately, to go there, all you have to do is haul yourself to Dulwich.