I've cheated a little in this park remix. The train line runs alongside Ramponi Park and I was fortunate to record a train when I visited to collect sounds for this track. The camera was recording from within the Park, of course.
Other than the train, the different sounds heard from the slippery slide are a highlight. It's great the way you can tap across the structure and getting the foundations for chord changes. And everything shares the key of the slide.