Opatija (Preluk)

Locally known as Preluk, this was a 6.000 km track in Croatia, used between the 1930s and 1977, when the track closed. It was also known as Abazzia in the 1930s, the territory temporarily belonging to Italy.

The track featured many gradients over the course, and these are as follows:-

   0- 150m  0.0% (5m)* 
 150- 900m  3.5% (31.06m) 
 900-1930m  5.3% (85.46m) 
1930-2065m  0.4% (86.00m) 
2065-2715m -2.4% (71.40m) 
2715-3865m -3.6% (30.00m) 
3865-4015m -3.0% (25.50m) 
4015-5015m -1.0% (16.00m) 
5015-5445m -2.0% (7.00m) 
5445-5645m -1.0% (5.00m) 
5645-6000m  0.0% (5.00m) 
* meters above the sea level on the end of section

It hosted international races (post-World War II) between 1950 and 1977, and bike races from 1969 onwards. GT and sportscar races were held between 1950 and 1959, Formula Junior in 1960, 1961 and 1963, and Formula 3 between 1964 and 1968. The track closed in 1977 due to increased driver hazards and boycotts by motorcycle riders - so the local auto-club hurriedly built the Rijeka (Grobnik) track to ensure that they could continue to host the Adriatic GP.