9b11f552____Final_Fantasy_X_2_Item_List__Location
[Name] Besaid Key [Description] Engraved with the emblem of Besaid. [Location] 
Buy at Besaid Item shop for 900,000 Gil during Chapter 1, or complete the 'Rescue Tourists' mission in the Calm Lands Gorge in Chapter 3, where one of the tourists you rescue hands it over.
Final Fantasy World - Final Fantasy X-2 Item List
Location