I love the celebration of the Grand Duke's official birthday.
Guillaume and Félix were in Esch-sur-Alzette this year. You can find photos here, here, and here. Also, be sure to visit the archive of tomwag.com and search.
There is also a video of Guillaume and Félix in Esch-sur-Alzette here.
Fireworks.....here...here...here...here... the last guy actually has a lot of videos of just walking around in Luxembourg that I found interesting.
Photos: APA, Tom Wagner, Getty, Cour Grand-Ducale, Wort