Alderney late 300s, at above the island's only natural harbour. The etymology of the island's name is obscure. It is known in Latin as "Riduna" but as with the names of all the Channel Islands in the Roman period there is a degree of confusion. "Riduna" may be the original name of Tatihou, while Alderney is conjectured to be identified with "Sarnia". "Alderney"/"Aurigny" is variously supposed to be a Germanic or Celtic name. It may be a corruption of "Adreni" or "Alrene", which is probably derived from an Old Norse word meaning "island near the coast". Alternatively it may derive from
Dana Island at the north of the island. According to some sources, French merchants also used the island as their port during Middle Ages. Dana Island Dana Island (, also called "Kargıncık Adası", Greek Latin "Pithyussa") is a small Mediterranean island of Turkey. Dana Adası lies parallel to south coast of Turkey at in the province of Mersin. The distance from the shore is 2.5 km. (≈ 1.55 mi or 1.35 nmi) The passage between the main land and the island which is known as Kargıcak strait is a convenient passage for maritime traffic. The shape of the island is roughly rectangular