In North America there are around 220 AZA accredited facilities, meaning that the Association of Zoos and Aquariums rigorously inspects each establishment at least once every 5 years. Only about 10% of all wildlife facilities are AZA accredited, and in my opinion even some of those have more than their fair share of dodgy animal exhibits. Some folks think that there are some great little zoos that are not AZA accredited, but I'd be shocked if they could name 5 that are even half-decent. For whatever it is worth, AZA accreditation in North America is a huge deal and institutions without it are for the most part substandard "homegrown" zoos, research facilities, etc.