@ThomasNotTom Yes these were the old bear pits from the early 1900s.
This photo from the 1930s shows how they originally looked: Polar bear enclosure
Most recently the enclosure held Sun Bears but these were moved to a new enclosure in 2012 and this one has sat empty since then. The thread below covers the progression of the new enclosure (post #1) and the old enclosure (post #2): Wellington Zoo's Sun Bear enclosure, in photos [Wellington Zoo]
@ThomasNotTom The whole thing is going to be netted over. Snow Leopards would be able to jump the moat there in a second (or go up over the back wall - there's really no way to do this enclosure for Snow Leopards without netting).