It’s easily visible on the north shore of the Caelid Wilds.
First, approach the tower from the south.
You’ll see two paths: one lower, which takes you to the tower base.

Using Torrent, hop from this branch onto the nearby ledge with the ladder leading upwards.
Jump over the gaps to reach the next ledge along.
Restoring Radahn’s Great Rune
Congratulations!

The hard part is over.
Very useful stuff, so it’s all worth the effort of scaling the Divine Tower of Caelid.

