I have found a few more old zoo photographs from my childhood in another photo album (see earlier uploads in the Borås and Kolmården galleries). The pictures in this album were dated so I know when they were taken.
Here is a series of pictures from Borås Zoo, taken in 1968.
This picture shows a little piece of the main enclosure for brown bears. About 1000 sq meters big, centered around a a genuine cliff it is nothing special today - and indeed it will be replaced by a 12 times larger enclosure in 2010.