I really love the design of this tower...thingy.
Or whatever it is supposed to be. I'll go with tower, ok?
The lava stream from the bill and the bottom of the tower need some work. Stronger lights and some darker spots would help alot. Look up some pictures on lava if you need a reference. Also, the lava flows at a rather inprobable arch at the bill. I recomment to study how different liquids flow in reality.
Last but not least, a bit of texturing would have given the tower a perfect, unsettling touch.
Other than that, I love the design, the shapes you used and the overall ambience. You shure can do some stuff and I would love to see you improve.
Hope my review helps :)