That first pic that Beast posted - it has the fun and saftey guide, as well as an arrow that says "ENTRANCE" pointing to the left. This picture would have been taken roughly where the back end of the old Flyers queue was, meaning to get to the entrance, you would walk into that entrance plaza directly across from The Vortex batwing element, and turn left and go behind the Rivertown bathroom.
In fact you can see the path itself - that sidewalk. It kind of starts behind that spool.