It was really nice to see people outside of an IBM office. There was grilled ham and Czech beer, plus ping-pong, volleyball, patonk, horses and nohejbal. I didn't understand what the heck 'nohejbal' was either...but it was a lot of fun.
Nohejbal (pronounded no-hey-ball) was invented in the ČR, in 1922, by members of the Slavia Prague football (soccer) club. It's also called football tennis or net ball. Basically, you are playing volleyball with a football on a tennis court. Since you're playing with a football (soccer ball) you only get to use your head or feet; no hands. One, two or three people play on each side of the net.
There have been European championships since 1993 and world championships since 1996. People here take it seriously.
Another colleague put together a video of the day's events. The music is Knipe by Tři Sestry, Three Sisters, a famous Czech punk rock band.