From the starting point, on top of the awning, drop down and head down the left path leading to the pool area. Ollie onto the left ledge and half way down at the left bend in the path you will see a rail that extends from the ledge, across the path, over to the main playground. Ollie onto or just ride up to the rail and grind it across the path for the bonus. If you're really tricky then you'll want to ollie at the end and land in a grind on either the picnic table or the ledge on the left.