Since its first edition in 2009, the Olimpíada has been a very successful annual competition for high school students in Brazil, with participants ranging from 30 to 45 thousand each year. Most of the competition takes place as an online test, which I discuss elsewhere and for which I also put up some posters I've designed.
As mentioned, the Olimpíada is mainly online, but at the end of five weeks of eliminating phases the ~300 best teams meet up in Campinas, home of Campinas' State University, where they take a written exam to determine their final standings overall. On the day after, there is an awards ceremony. The images below are from the 8th ceremony.