Gustav Havel's 300 turns is the Open Championship of the Czech Republic on natural circuits and the Championship of the Czech Republic on natural circuits, which has been held in Hořice in Podkrkonoší since 1936. The name originated from the fact that after twelve laps of the race, a motorcyclist will complete exactly 312 turns on the Hořice racing circuit.

Since 1968, the race has been named after Gustav Havel, a Czech racer who was one of the world’s top racers and tragically died in 1967 on his way to work.