This exhibit has recently been enlarged by removing the pool in it. From 1968 to 2005/2006 it housed polar bears and a large part of the area you see in this photo was filled with water, you can see the line on the concrete wall where the surface used to be. When the snow leopards moved in in 2006 the water level was lowered and only the lower area to the right was filled. Now they have emptied the pool completely to enlarge the exhibit.
@Anton Thanks for the fascinating information. It was probably great to see Polar Bears in the rocky enclosure back in the day, but now it's a world-class Snow Leopard exhibit.