The first requirement for playing this seed is that you must use version 1.2. There is a cross ravine generated with your spawning place closely. The establishment of this special terrain is similar to two ravines, which is a typical feature of version 1.2.
How to Play Cross Ravine & Plains (1.2 Beta Only) Seed
After you spawn, you need to turn around and no longer meet the cross ravine. Next, turn left and go ahead about 50-100 blocks, you will find the cross ravine immediately.
It is obvious that Cross Ravine & Plains (1.2 Beta Only) Seed is a perfect option to experience.