Atop the roofs, you can whip your enemy into the helicopter. You can jump off at the airconditioner at the central left area, as well as on the bat signal at the far left end. The water tower at the far right can be knocked over for further damage. After the shower, it's time for one of the most painful-looking transitions at the far right end. Below at Crime Alley, the fire hydrant at the far right can be used for more water-splashing, while the neon sign above it can be thrown at. The dumpbin at the center area can be kicked into your foe unlimitedly. The Ace Chemicals truck at the far left end can be used to shoot toxic liquids. The transition back to the rooftops is at the far left.