Unst, Yell, and Mainland are part of which island group?
Unst Unst Unst () is one of the North Isles of the Shetland Islands, Scotland. It is the northernmost of the inhabited British Isles and is the third largest island in Shetland after the Mainland and Yell. It has an area of . Unst is largely grassland, with coastal cliffs. Its main village is Baltasound, formerly the second largest herring fishing port after Lerwick and now the location of a leisure centre and the island's airport. Other settlements include Uyeasound, home to Greenwell's Booth (a Hanseatic warehouse) and Muness Castle (built in 1598 and sacked by pirates in 1627); and Haroldswick,
Unst and Fetlar are mainly formed of ultramafic and mafic igneous rocks which are interpreted to form part of an ophiolite, a section of oceanic crust from the Iapetus ocean which was destroyed during the Caledonian orogeny. Unst was once the location of several chromite quarries, one of which was served by the now-disused Hagdale Chromate Railway from 1907 to 1937. Unst is the type locality for the mineral theophrastite, a nickel-magnesium variant of the mineral, (Ni,Mg)(OH), having been discovered at Hagdale in 1960. Ferries link Belmont on the island to Gutcher on Yell and Oddsta on Fetlar. The Unst Bus