We went twice to this park during our week's stay at Landal Coldenhove. We used 1 free white bike and hired a tandem (10 Euros) so our 5year old son could cycle too.
We took a picnic and cycled for miles and miles through the quite amazing forest scenery one minute and African plane style scenery with natural sand the next.
The underground museum is fascinating and worth a visit too and there was a farmers market there during our weekend visit.
Well worth a visit.