Looking at the pictures, it appears that they created this to have a modular design. The front Seems to have a little tab that will allow something to connect to it... I'm thinking it might be one of those battle arenas like this one.
The sculpted "lava" on the right side has two pegs on it. I'm thinking the little pads that Obi-Wan and Anakin are on actually go on that.
Okay... it does all that per the box. Apparently, it comes with the two figures as well. There doesn't seem to be a lot going around on the "inside" but that appears to have tabs for more things to be connected to it.