When passing Amersfoort , visiting Camper Centrum
Nederland
http://www.campercentrumnederland.nl/
is a must imo. vistit the best Cali dealer in the BeNeLux , see the biggest collection of new and used Calis and look at their shop full of goodies.
They let you spend the night on the parkinglot witch is in industrial zone , quiet at night , security passing frequent . If you read some of my treads or search you can get a preview on what to expect at their place , you need at least 1/2day to visit them!
Coffee and toilets during opening time
Been looking once at the habour spot Eemhaven, not that great place but free, with only three places it was full at the time , did not spend the night. Probally full most time during summertime.
Maybe
@bvddobb can give some tips in the area?