Alderney is the northernmost of the inhabited Channel Islands. It is part of the Bailiwick of Guernsey, a British Crown dependency. It is 3 miles long and 1+1⁄2 miles wide. The island's area is 3 square miles, making it the third-largest island of the Channel Islands, and the second largest in the Bailiwick. It is around 10 miles to the west of the Cap de la Hague on …Alderney is the northernmost of the inhabited Channel Islands. It is part of the Bailiwick of Guernsey, a British Crown dependency. It is 3 miles long and 1+1⁄2 miles wide. The island's area is 3 square miles, making it the third-largest island of the Channel Islands, and the second largest in the Bailiwick. It is around 10 miles to the west of the Cap de la Hague on the Cotentin Peninsula, Normandy, in France, 20 miles to the northeast of Guernsey and 60 miles from the south coast of Great Britain. It is the closest of the Channel Islands both to France and to the United Kingdom. It is separated from the Cap de la Hague by the dangerous Alderney Race.