Why is Sponge Bob in Platteville?

Earlier today I found myself driving down Hwy. 66 in Platteville and along the southern side of the street there is what looks like a large farm or ranch, but they have some odd things outside. There was a huge Sponge Bob, a NASA space pod, the car from the movie Ghostbusters and more. Does anyone know what this place is or why they have this stuff? It was cool, but kind of strange...