Since we are based in Amsterdam, we follow the (few) public holidays in the Netherlands. Today is Kingsday! Literally the King Willem-Alexander's birthday. This tradition which started as Princess' Day in 1885 has been carried on by the Dutch monarch ever since.
While it may not sound like much, King's Day is probably the largest national party in Europe. The streets of the entire nation flood with people dressed in orange (the national color and color of the monarch) and alcohol flows freely.
If you aren't in the Netherlands while reading this, have a look at the live streaming cams below which are located throughout Amsterdam and catch a glimpse of the largest party you have ever seen. Also, perhaps more importantly, start planning your trip for next years celebration.