In Dutch

On June 8, 2012, His Royal Highness Prince Willem-Alexander of Oranje was at the Olympic Stadium in Amsterdam to open the 10th Edition of the School Mission Olympic Finals.

According to RVD, the Mission Olympic is:

… a school sports competition where 315 high schools in Netherlands to participate. After the opening competition over 5,000 finalists in eighteen different sports categories at various sports venues in Amsterdam compete for the National Championship for secondary schools.

Source: RVD/HKH