Minecraft Forums

None of my old saves are showing up within minecraft. I can see all the folders in the save folder and new saves show up fine. I've tried backing them up and deleting .minecraft to force it to recreate the file but it still isn't working when I put the saves back in the folder.

How old are the old saves? Minecraft will only display saves that are in a format that it understands which is the 'current' format and the 'previous' format for whatever version of minecraft you are trying to run. So 1.6 will displays Anvil and McRegion format saves only. Really old saves that are in a different format won't show up because minecraft doesn't have the code to support upgrading them to Anvil format.

I'm not sure exactly how old the save files are but it seems the level.dat files have gone missing and all that is left are the files in the region folder. The Region files are .mca files though. I tried inserting a fresh level.dat file into the folder but it just generated a new world.

The original level.dat files are key. Using a different one will not give you good results.
It will change the seed and other world generation parameters (structures, world type, biome size,etc) and thus world generation, your location* and inventory. The world seems different because your location changed. If you traveled back to the portion of the world you had previously been in you would start loading the old chunks and seeing the world you expect (with weird boundaries between the old chunks and the new chunks generated with a different seed).

MCA is anvil format (the latest format) so that's good.