Zipline Racetrack
Um'Kala is a big district of Nar Shaddaa, and ever inch of it has been turned into some form of deadly entertainment, including the rooftops. Jumping between roofs, from high to low and in reverse, the Zipline has more open air than might seem reasonable, but it's a great place for betting to happen. How long will a pod stay in the air? Can the driver do a trick? Will the driver skip roofs or take a shortcut?
A straight shot route from one end of Um'Kala to the other, Zipline is a racetrack in name only, because really its just a race from point A to point B.