@black_box, dunno what the tower is for. It's located just past the end of the longer runway at Anchorage International Airport, so it probably has something to do with them.

@GRedner, Nokian Extremes (the 29er version, in this case). It's really neat that they accelerate hard and that you can go as fast as though you were on pavement, but you still have to corner slowly and carefully (or fast and really wide, and carefully).