Bordeaux is a world capital of wine, with its castles and vineyards of the Bordeaux region that stand on the hillsides of the Gironde and is home to the world's main wine fair, Vinexpo. Bordeaux is also one of the centers of gastronomy and business tourism for the organization of international congresses. It is a central and strategic hub for the aeronautics, military and space sector, home to international companies such as Dassault Aviation, Ariane Group, Safran and Thalès. The link with aviation dates back to 1910, the year the first airplane flew over the city. A crossroads of knowledge through university research, it is home to one of the only two megajoule lasers in the world, as well as a university population of nearly 100,000 students within the Bordeaux metropolis.