The last was Toronto zoo - a few years ago. I'm not a zoo or Sea-world kind of person anyway, and it really put me off zoos, innocent-creature prisons - the living conditions for some of the inmates was appalling at that time, very distressing to a sensitive dude like myself. I'm surprised to see the enterprise is still in business. One of the best, most enthralling, zoos I visited was Dunstable - but that was many decades ago.