This is an overnight stop after taking the ferry if you are heading towards Belgium, Holland or Germany. It is called the Aire de Ghyvelde (I may have spelt that incorrectly). It is the first reasonable place to sleep for one night but nothing more. The advantage of it is that you can take advantage of much cheaper ferry crossings - I think I paid GBP37 in September 2012, for the car I think it is GBP20 or GBP25! Furthermore there are several lay bys in the UK before getting into Dover where you can rest before taking the ferry.