Dark Souls Remastered | Archive Tower Giant Cell Key location, starting from bonfire by Crystal Cave

*Not to be confused with the Archive Tower Giant Door Key.*

The Door Key is necessary to get out of the area you spawn at after dying at the first encounter of Seath the Scaleless. This key is not that. This is found later on, after the third main bonfire of Duke's Archives, which is the bonfire on the balcony near Crystal Cave, sometimes called Duke's Archives 3.

This key opens the cell at the very bottom of the spiral staircase area. Within it, there is a Fire Keeper Soul, which is a very good item because it reinforces your Estus Flask. You can only reinforce it so many times. This is not a necessary item, but it's still great to get.