German Championships Cross TriathlonWhat began in 2000 with a bet, today presents itself as a cross-triathlon location of international standing. Five cronies jumped into Lake Olbersdorf to compete - and unconsciously laid the foundation for the O-SEE Challenge. Since 2004, the event has positioned itself - within the worldwide XTERRA series - as the most famous and demanding cross-triathlon in Germany, with around 1,500 starters from all over the world. The O-SEE Challenge is Saxony's most international triathlon event.