I went visiting the Digiport in Lille (north of france).
they provides a full range of services for IT companies from a business park to host your business to personalized support for your incorporation.
I was really impress by the quality of the infrastructure and the skills of the team.
If you are a startup CEO looking for the perfect place for european headquarter, you should really consider this place.
Cherry on the cake: By the high speed train, London is at 1h20, Brussels at 30 mins, Paris at 1h and charles de gaulle airport 40 mins.