It is prior to 1971 as the big eagle aviary adjacent to the birdhouse is not on the map and that came in 1971.
It is after 1951 which is when the aquarium was established.
That leaves a time frame of 1951-1971. It should be prior to 1970 because then the gorilla came and it would be strange those not to mention on the map.
Orangutan are shown in the picture. These were according to ZTL in Wroclaw and during that time frame: 1927-1963 (Sumatran), 1969-1973 (sp not defined).
The Japanese Gate, the second entree which should be on the upper part of the map, behind the Reptile House, is not shown. It was closed in the 1960's (and reopend not before 2009). I could find a more specific date of closing.
So my guess is this map dates from 1969-1970 but maybe @Kranich29 or @Peter could help you better.
Thanks very much for your analysis. There is a small set of numbers in one corner of the pamphlet and they end with a slash mark (literally this: /70) and so I was guessing it was the year 1970. It is weird that the Gorillas are not there, but perhaps this map was published early in the year, before the Gorillas were added.
@snowleopard Wroclaw Zoo maps from the past are pretty messy. I've collected a couple of oldies but they tend to be underdetailed and often not too informative.
Eagle aviary is not on this map, but it isn't shown on the modern one too.
I dug around the internet and found this page Index of /zoos/europe/pologne/wroclaw/maps
The photo you sent is there labeled as a file with a date 1970.