Tree tunnel  A tree tunnel is a road, lane or track where the trees on each side form a more or less continuous canopy overhead, giving the effect of a tunnel. The effect may be achieved in a formal avenue lined with trees or in a more rural setting with randomly placed trees on each side of the route. The British artist David Hockney has painted tree tunnels as a theme, as especially illustrated at a 2012 solo exhibition of his work at the Royal Academy in London, England. The English landscape artist Nick Schlee has used a tree tunnel as subject matter.