Muckle Flugga is a series of rocky islets off the north west coast of Unst in Northern Shetland and until 1995 formed the most northerly human inhabitation in the United Kingdom. The inhabitants were the lighthouse keepers who manned the North Unst lighthouse. This lighthouse was built by David Stevenson in 1858 with a light visible for twenty-one miles. The lighthouse was automated in 1995.