The Altar of Dagon (aka Dagon's altar) is on Black Tern Island. It is accessible by boat from the Παραλίμνιο. It is served by an acolyte of Dagon and is where sacrifices to the deity are brought, and so is the location of Γκέραλτ's duel with Dagon. After the duel, it is also where the Lady of the Lake speaks to Γκέραλτ about Destiny, knights him and gives him Αερόντιγκτ.