5-D Space is one of the thirteen network levels in Marathon 2: Durandal.
5-D Space is a very confusing level, in that, if you go around a certain corner, you will end up in a different dimension. (You will not be able to find any players in the other dimension without leaving this one, but they will show up on the map.) This alternate dimension is the same size as the other one, but there are a few differences: The walls look different, and there is a door at the end of one hallway that leads to a dead end room. (Useful for hiding out.)
There are no known secrets on this level.