There are several altars to Melitele in the game, but only two that are usable:
- One can be found in Νοσοκομείο της Αγ. Λεμπιόντα, in the Συνοικία του Ναού.
- The other Shrine of Melitele is located in the Swamp.
Acceptable sacrifices: fruits, plants, Λουλούδια or food on the altars, specifically, only sacrifices of fresh fruit like grapes, blueberries, raspberries, dried fruit like the dried fruit and nuts or plain dried fruit and herbal flowers, like beggartick are worthy. Surprisingly (perhaps only to me!) meat of any kind is also an acceptable sacrifice, so any food item seems to work.
Unacceptable sacrifices: "regular" Λουλούδια like tulips, orchids, roses, etc. ... are not acceptable.
The first sacrifice will give you three of the Sephirot: Ghe'vrath, 'Oth, Veen'ah. You will need these for the A Mysterious Tower and Monoliths tower quests. After this, every subsequent sacrifice will give you Ιξός, an alchemical ingredient.