Extreme Chase is partially inspired by real world landmarks, such as this Park Entrance.
Previous part mentioned fountain's pump station built in form of a castle. This is how the real-life fountain near the castle looks:
While it has an interesting shape, gameplay wise it would take a lot of space without any verticality. There's another existing fountain, and one does not simply walk past it without thinking how fun it would be to jump and jump till you reach the top of it.
You can see that jumping in action at 1:05 here:
Or try it yourself here: