The ‘Sultan’s Way’ ends at the Austrian Capital of Vienna where I arrived  yesterday,  to find the Leopold Gallery replete with its own images of the Horse Chestnut Tree. The tree itself arrived in Vienna in 1576 at the instigation of Carolus Clusius, the imperial director of the botanical gardens and today there are over 20,000 of this species living along the city’s streets. It has clearly been an inspiration to Viennese artists.