Battle Course 3 (SNES)
From the Super Mario Wiki
Battle Course 3 is the third battle course of Super Mario Kart. It uses the Vanilla Lake tileset. Its form is a square, with walls and breakable ice blocks. The arena's floor is completely slippery, making it a bit harder for players to get an exact strike on someone. It also makes the level a bit easier to drift on, causing obstacles such as bananas to be completely missed.
Although they didn't appear in Mario Kart: Super Circuit, tilemaps and minimaps exist for all four of the Battle Courses from Super Mario Kart. These could have been used as placeholders before the new ones were completed, or it may have been possible to unlock these courses like the tracks at one point. Unlike all other tracks and battle courses in the game, which are stored in chunks, these are each stored in one piece, as in Super Mario Kart.
Also, prototype pictures show that this course used the Choco Island tileset at one point.