On Thursday the 17th , and Friday the 18th of October , the Ziggo Dome will be completely taken over by the show: OUR STORY 15 Years Tomorrowland. Travelling to Amsterdam is a part of all the special festivities that are being held this year to celebrate the 15th anniversary of Tomorrowland. Tickets go on sale on May 25. Pre-Registration is now open: my.tomorrowland.com , , The first edition of Tomorrowland took place in 2005 and in the meantime , the festival has grown into the most popular and spectacular music festival in the world. This year , the 15th anniversary will be celebrated in all kinds of ways , such as the recent launch of Tomorrowland - One World Radio and Tomorrowland Winter in Alpe dHuez (France).