Junction of Worlds
The Junction is a tiny universe, whose borders are entirely shrouded by a thick fog, with the only sign of anything beyond being the occasional flash of multi-colored light. The space within the Junction is entirely taken up by the ruins of an ancient structure, with the only parts that are still intact being a massive array of intricately carved doors. Each of which is actually a gateway into another universe.
These doors are arranged in a series of rings, with the number of total doors being in the hundred, or even thousands. The rings of doors are split by four wide pathways heading out at right angles. Two of these pathways end in massive doors that are very different in design from both the regular doors around them, as well as each other. One is lighter in color, and bears a colored image of a globe, while the other is darker in color, and is painted with various death-related images.