Campsites for route planning in Europe

One of the commonly asked questions on forums like this is 'Can anyone recommend a site near..............' or 'on the route between'.  A website which is very useful for finding en-route campsites is Leo Huybrecht's website - Camping near the main routes.  It lists all sites within 15 km of the major routes through Europe, and gives opening dates, POI's and various other information.  It also highlights (in red) those sites which are open all year.  Used in conjunction with the Caravan Club Europe book it may just help with your route planning and site finding.