Random Pick #5 from My Collection.

The Babylon Tower (a.k.a. Ivory Tower), invented by Arxon Spiele and Freizeit in 1981 and manufactured by Ideal, is a slide puzzle comprised by six gradient colored balls in six columns. The main goal may not be visible at first but, it's simple: You push a ball from the bottom, to a hole inside the tower, thus creating a gap for the rest of the balls to move around. You  can move a ball up or down or just rotate one of the six discs. It's a simple 3D slide puzzle just like the Whip-it, the Varikon or even the Missing Link.

I personally love this type of puzzles (3D rotational/slide puzzles). Not because they're easy but, because they're very fun to play with. You can check several of these puzzles in the Slide section of my collection.

There's another darker version of the Babylon Tower, although it's much harder to find it. Besides the classic version, there's also two other versions as well. A Key-chain and a Junior (with only four balls). Along with the different versions of the Ivory Tower, you can also have different package versions (refer to the puzzle case), like French or German. I have a French one and you can read on the case "Babylone Tower".

You can still buy one at Puzzle Master.