The police station in Irun, a border town between the Spanish and French states, has the highest inter-annual data of arrests of foreigners in irregular situations when compared to other police stations in the Basque Country. This pattern, of which many are unaware, is due to police identity checks in the border surroundings. The place where the border barrier was once, was occupied by a car toll booth constructed with a very particular structure: as a border, with cabins for police officers. In addition, the data for border readmission between these two states, under an agreement signed in 2002, requires special attention: 300,000 people were deported across the Northern border. 70% of the people detained in the French Detention Centre at Hendaia in 2015 were caught at the border. This case study on the Spanish-French border will shed some light on a disregarded topic: internal borders. Regulation in these areas is diverse. Many exceptions and specificities apply, in parallel or alternatively to the ordinary immigration rules, as a matter of exception to the law. In considering this, we need to rethink the image of a borderless Europe as stated by the Schengen agreement. Since the publication of Balibar’s essay ‘What is a border?’ (2005), the controls have multiplied all along the territory as a kaleidoscopic vision. The eu internal borders have never disappeared, but have mutated into a police managed model of internal borders. [ABSTRACT FROM AUTHOR]