"UNST, a parish in the Orkney and Shetland islands, Scotland. It comprises the most northerly of the Shetland Isles, including Unst, Uya, Balta, and many smaller islands, as the Skerries, off Skaw Head, and the Outstack rock, being the most northerly point of the British Isles. It is of an oblong form, extending from N.N.E. to S.S.W.; in length about 11½ miles, with a mean breadth of about 3½ miles. The coast is rocky, and is indented by bays and creeks. In the W. and N. the headlands sometimes reach an altitude of 400 feet. On an outlying conical rock 201 feet in height was erected in 1858 a tower 60 feet high, which serves as a lighthouse, 4 miles from Burra Fiord."
From The National Gazetteer of of Great Britain and Ireland (1868)