On the southwest corner of Schlossplatz is a modern landmark.The facade of the Kunstmuseum changes depending on when you pass by.By day it’s a large, reflective glass cube.But when the interior is illuminated at night you can see the limestone walls behind the glass.The design of the galleries inside is also exciting as they make use of a 5,000 square-metre system of disused tunnels in a subtle and imaginative way.The museum was born in 1924 on the back of a donation by Count Silvio della Valle di Casanova and covers Swabian, German and Swiss art from the 19th and 20th centuries.