The Phoenix Zoo in Arizona has a walk-through squirrel monkey exhibit that has about 18 monkeys and is simply outstanding. How many monkeys are in the London Zoo habitat? Are the crowds of people overwhelming at times?
The monkeys are certainly very good at getting out of the way - this was the first time in several visits I'd actually seen them outside rather than in their indoor accommodation (whcih can be viewed just outside).
For ultimate Squirrel Monkey walkthrough, Apenheul in the Netherlands had (I believe) around 200 monkeys in a massive area of woodland. That was something of an experience. London has about 10 or 12, I think.
