Quick path to the Seren's Memorial crystals: * Start in the Sanctum, exit south into The Approach; * North, traverse the rock formation bridging a lavafall; * West, south, climb rock formation with black spikes; * West, walk across rock formation with purple healing crystals and climb down the Cliffside; * East, cross rock bridge into the area with crystal pillars. You will be in an area with four pillars and four inactive crystals. One of the pillars will be active, and can be tagged. Tagging 80 active pillars will unlock all four crystals.