Tsukuba Circuit, located in Japan, was built in 1970 and is known for hosting sports car, open wheel and motorcycle races - and most notably Time Attack competitions. There are two main configurations, Course 1000 and Course 2000, with multiple variations of both. This makes the track a perfect fit for the iRacing base package as it can be used in multiple series without becoming repetitive.
Course 2000 is just over 2 KM in length and features 14 turns. Course 1000 is approximately 1 KM and has 11 turns. While the two main configurations share the same facilities, they are completely independent of each other and don't share any racing surface.
The tracks proximity to Tokyo, Japan has made it extremely popular with local car tuners who compete in Time Attack competitions. Expect to see Tsukuba Circuit feature in both race series and time attack competitions on iRacing.