I did not expect that and agree with @Leedle95 . I do not assume the public will be allowed to go there even in off-seasons as a pedestrians.
But the bus enclosure would have a case for safety if it is as you describe it IMO. Just remember the golden rule to stay aware of the 
surroundings 
.
The bus enclosure sounds really cool. Though at the same time, it makes me feel very sad for the Tigers.
This zoo is a very special place. They donate money and are a part of the european endangered animals program. And I think the animals have it pretty good there. There are several animals that doesnt usually breed in captivity, that have been given birth at this zoo. Among the species dolphins, rhinos and and gorillas, and that is good sign that the animals are happy and feels safe in their enviroment.
Update regarding the poi. It was reported and succesfully removed a few days later! Thankyou for all the answears!