The Walnut Log is a Crafting Material in Final Fantasy XIV: A Realm Reborn
Zone
South Shroud
Node
25
Level
24
Landmark
Quarrymill
Uses
Mid-high level ACN weapon (ALC), plus Walnut Lumber, in turn used in a tremendous variety of mid-high level tools, weapons, etc. made by BSM, CRP etc.
Useful?
Yes, Walnut Lumber conversion. Even early (NQ) farming works, and you'll use a lot.