Sun Wukong are you sure this is exhibit for Sumatran tigers? I always remember it as Snow Leopard exhibit, but I have to admit I was not there last three years (I spent much time in the zoo in Bratislava, but last three years I ignore it).
This always used to be one of my favorite exhibit. It is not large, but it is situated on almost non-visited trail, so it is quiet place between the trees in the forest. Very nice surrounding for snow leopards. And it is one of the most naturalistic exhibits in the zoo...trees, stones, grass... and good possibilities for climbing (the rock wall, and also the steep hole in the front). I think it is really nice place for smaller snow leopards, but not for tigers!
I dont know how old is it, but I remember it for at least 18 years.