An Arm and a Leg

 An Arm and a Leg was a virtual representation of one of Kassandra's genetic memories, relived by Layla Hassan through the portable Animus HR-8.5.

Riddle
''How much does a temple cost? Head southeast to the Sanctuary of Asklepios. In the temple, you'll find me among the donated limbs.''

Outcome
Kassandra found and recovered the treasure.

Reference

 * Assassin's Creed: Odyssey