 There are numerous important prehistoric remains in Orkney , especially from the Neolithic period , four of which form the Heart of Neolithic Orkney UNESCO World Heritage Site that was inscribed in 1999 : Skara Brae ; Maes Howe ; the Stones of Stenness ; and Ring of Brodgar . The Knap of Howar Neolithic farmstead situated on the island of Papa Westray is probably the oldest preserved house in northern Europe . This structure was inhabited for 900 years from 3700 BC but was evidently built on the site of an even older settlement . Shetland is also extremely rich in physical remains of the prehistoric eras and there are over 5 @,@ 000 archaeological sites all told . Funzie Girt is a remarkable Neolithic dividing wall that ran for 4 kilometres ( 2 @.@ 5 mi ) across the island of Fetlar , although the Iron Age has provided the most outstanding archaeology on Shetland . Numerous brochs were erected at that time of which the Broch of Mousa is the finest preserved example of these round towers . In 2011 the collective site , " The Crucible of Iron Age Shetland " including Broch of Mousa , Old Scatness and Jarlshof joined the UK 's " Tentative List " of World Heritage Sites . 
