Complex sentence: Twice a year, there is the "Freiburger Mess" held on the open-air grounds; it is the largest funfair in the region and attracts up to 170.000 visitors.
Split into simpler sentences: Twice a year, there is the "Freiburger Mess" held on the open-air grounds. It is the largest funfair in the region and attracts up to 170.000 visitors.