The Iris Festival is the annual and official celebration of the Brussels-Capital Region in Belgium. It takes place on 8 May and is a day off for Brussels officials.
The date of 8 May was chosen for three reasons: it takes place during the flowering period of the yellow iris—also called flower of Lys—which is the symbol of the region and is pictured on its flag; it is the day of the victory against Nazi Germany during World War II; and it is also one of the feasts of Saint Michael the Archangel, patron saint of the City of Brussels.
During the multi-day party, free concerts, street entertainment and all kinds of activities are organised for the general public. Some monuments are exceptionally accessible to the public, and a food truck festival takes place on this day. In 2008, there were 100,000 participants at the festivities. Since 2015, Rock Around The Atomium has also been organised at the Atomium in this weekend.