It’s said to be the world’s largest art exhibit, 110 kilometers, and 94 stations which are decorated by some 200 artists. Welcome to a 1000-piece art tour in Stockholm’s subway system. Motif: Solna Centrum Station A spruce forest runs for almost 1000 meters along the walls, underneath a blood-red sky representing the depopulation of the sparsely populated area and the environmental degradation of nature.