Nordshleife will soon be the second longest race track in the world! Wait what? It looks like Swedes are crazy enough to build "multipurpose race & test circuit network expansion, total of 28 km with six major separate circuits that can be utilized simultaneously"! Moreover Gotland Ring will also have the longest modern standard race track by 2011 (7.4km).
Check out their website for time schedule:
Gotland Ring from Anders Bäckman on Vimeo.
Here is the layout: