Closer than you think!
Apenheul is situated less than 45 minutes from Utrecht and Nijmegen, and from Amsterdam you can be walking amongst the primates within the hour.
The way to Apenheul is clearly signed in and around Apeldoorn. There is plenty of parking available near the zoo. From the car park, cross the street and walk straight onto the pavement. Follow the path to the left alongside the pond, in the direction of Apenheul.