The old bear grotto! European brown bear. As it seems, it is nowadays only used for a mother bear with her cubs. 300 or 400 square meters big, with noisy visitors at all four sides. Not good at all! The only good thing about it is that the den is available at all times, when the screaming kids get to noisy.
BTW:
This "exhibit" is one of my earliest zoo memories. I saw it as a child, some 40+ years ago - it looked BIG then, to my childish eyes! And THEN you could buy "candy" to "feed" the poor bears...