This newly renovated enclosure is a part of the project " City windows overlooking nature" which includes educational trails and centres for interpretation of the living world around the whole Maksimir park.This exhibit is next to the Carnivores of Croatia educational display.
I think there were few concrete grotos for bear species here before.
Yes, prior to the renovation, there were 3 bear pens. Till 1999 they also have polar bears. So, this wall is part of old enclosures, but in the past, it didn't look like that. I agree that now it have "polar look".
