How many locations are there in Minecraft?
Solution 1:
These "locations" are called "dimensions".
This is it, three of them - Overworld, Nether and the End. Mods add more, of course, such as the Aether.
Solution 2:
From the Minecraft Wiki: There are currently 3 dimensions: The Overworld (the "normal" gameworld), The Nether (a "hell" dimension), and The End (a sparse floating island, home to the Enderdragon). All three are surrounded by The Void. Other dimensions can be added by Mods.