Why doesn't a downloaded map show up in Minecraft?

Solution 1:

I did all the steps, but it won't show up in the single player section. I double checked everything, also the resources packs.

Your map is .rar and must be extracted. When extracted, all of these kind of files in a folder must be required:

There should be a level.dat file. Which is important. Cut the foder and paste it to the saves folder. Be noticed that your map doesn't shows at the top of your singleplayer section, so find the map and play it.

Solution 2:

I'm assuming that the map you've downloaded doesn't appear in your Singleplayer section?

If so, then double check if it's in the right directory. %appdata%/.minecraft/saves

If it is, then there might be a common issue that the actual map is inside the folder you've dragged. (Just check the folder that you've dragged, it should look something like this: