I don't know for sure but I'm going to guess it was when the zoo first opened, there is another similar photo below it that appears far more recent (1980'sish) and the crowds are nowhere near as heavy as this.
I have a photo of it somewhere on my laptop, will dig it out and upload it later!
I don't know for sure but I'm going to guess it was when the zoo first opened, there is another similar photo below it that appears far more recent (1980'sish) and the crowds are nowhere near as heavy as this.
I would also guess it was taken on a Bank holiday, though I see some overcoats so maybe not the Summer one. Bank holidays traditionally have always been a big day for Zoos.