Separate tunnel for pedestrians, cyclists and scooters connecting Huandao North Road and Gang'Ao Avenue. The tunnel is wide, well lit and decorated with numerous murals along its way - though it would have been even cooler if it was covered all the way ;-)
Highlight is probably the jet painted at the ceiling that uses the ventilation fans as its jet engines (though it appears the wings are painted forward sweeping, so probably it wouldn't actually fly).