In Prague ZOO you can just come to the lemur space (wouldn't call it a cage as it is huge) and watch them really closely. Some are not afraid of people at all and will come just few cm(!) close. Then you can watch them playing, grooming or eating. The shy ones aren't suffering as they have plenty of space to hide there in as well :)
Prague ZOO is rated one of the best ZOOs in the world, I really recommend visiting if you have the opportunity!
