But is it art?

I went to the Tate Modern this weekend to look at the latest installation in the Turbine Hall (the seventh since the inception of these installations in the main hall). It is a tube construction by German artist Carsten Höller. It consists of five steel tubes, each of which allows people to slide down inside the tubes, wrapped in some sort of cloth. One of the five tubes extends from the top of the Turbine Hall all the way down to the main hall floor.

Naturally this attracted quite a few people (and of course a lot of children) to visit the Tate. And it seemed that not only the children enjoyed this kind of entertainment. I just asked myself did they come for the art or the entertainment? And how different is this tube construction (aka art) from the ones found at fun fairs?