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Greetings Space Cadets, The Churchill Barriers are a series of four causeways in the Orkney Islands, United Kingdom, with a total length of 1.5 miles (2.3 km). They link the Orkney Mainland in the north to the island of South Ronaldsay via Burray and the two smaller islands of Lamb Holm and Glimps Holm.
n 14 October 1939, the Royal Navy battleship HMS Royal Oak was sunk at her moorings within the natural harbour of Scapa Flow in a night-time attack by the German U-boat U-47 under the command of Günther Prien.
The barriers were built in the 1940s primarily as naval defences to protect the anchorage at Scapa Flow, but now serve as road links, carrying the A961 road from Kirkwall to Burwick.
The barriers are numbered from north to south. In 2016, Historic Environment Scotland designated barriers 3 and 4 as Category A listed buildings.
Follow the whole expedition across Orkney and beyond here.