This looks like soooooooooo much fun and much safer than the Running of the Bulls! ( Can you imagine how it would feel to get squashed by one of these? ) If you look at when they enter, you can see that it's just a big hollow inflatable ball :) the water on the inside allows them to slide, and not tumble over each other while the ball is rolling down the hill. So basically it's a bubble water slide. Of course it would help if you were around 20 years old but it is still a lot of fun to watch on the ole computer screen. Best viewed full screen in your highest resolution, sound up! stokedforsaturday.com