I stumbled across a very choice rune farming spot in Elden Ring. There are enemies that give 1K runes per kill and are pretty easy, especially if you sneak up and shank them in the back.
To get there you'll first need to make your way the Third Church of Marika, map location below:
From there go north east across the river to this location:
There will be a teleporter in that location that looks like this:
Use it and it will take you to the Bestial Sanctum. Don't engage the big baddy in front on the building, it will kick your ass into outer space. Instead, sneak off around the left and go and hunt in this location:
Sneak up and shank those suckers and you'll get 1K of runes a pop. There are around nine or so roaming around the area. Once you kill them, teleport back to the Bestial Sanctum. Rinse and repeat. I went from level 22 to 47 in a couple of hours.
These are what you are looking for:
Ewok celebration time!