ATTENTION: Always make backups before deleting files from your world.
Chunks To Keep
Dimension : DIM1 (The End)
-3, -3
-3, -2
-3, -1
-3, 0
-3, 1
-3, 2
-2, -3
-2, -2
-2, -1
-2, 0
-2, 1
-2, 2
-3, -3
-3, -2
-3, -1
-3, 0
-3, 1
-3, 2
-2, -3
-2, -2
-2, -1
-2, 0
-2, 1
-2, 2
-1, -3
-1, -2
-1, -1
-1, 0
-1, 1
-1, 2
0, -3
0, -2
0, -1
0, 0
0, 1
0, 2
1, -3
1, -2
1, -1
1, 0
1, 1
1, 2
2, -3
2, -2
2, -1
2, 0
2, 1
2, 2
Dinnerbone's Region Finder Tool
You can use Dinnerbone's tool to take co-ordinates in your world and find out what regoin file they are in.