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
Juan de Nova Island southern fringing reef in 1911. Juan de Nova Island Juan de Nova Island (French: "Île Juan da Nova" (official), "Île Juan de Nova" (local)), also known as Saint-Christophe, is a French tropical island in the narrowest part of the Mozambique Channel, about one-third of the way between Madagascar and Mozambique. It is a low, flat island, in size. Anchorage is possible off the northeast of the island which also has a airstrip. Administratively, the island is one of the Scattered islands in the Indian Ocean, a district of the French Southern and Antarctic Lands. The island is garrisoned by French