It depends on what you are talking about.
For instance, if you are talking about the point comprising all possible time lines for all possible universes then the point comprises the tenth dimension. Here is a great flash animation that will help you understand the point in the first, fourth, seventh and tenth dimensions and what goes on in the other dimensions as well.
You may have much more interesting dreams if you study this right before bed! Oh, there may be some altered states of consciousness in which you can better visualize these concepts.

Via the apostropher.