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Harry's Walls is an unfinished 16th century artillery fortress located on the Isles of Scilly off the coast of Cornwall. The castle was constructed during the reign of Henry VIII as part of a programme of coastal defence against French and Spanish invasion, reflecting the strategic importance of the Scilly archipelago in Tudor military planning. The structure comprises a distinctive low-lying gun platform with angular bastions designed to accommodate and protect cannon, exemplifying contemporary fortification principles of the period. A prehistoric standing stone, known as the Mount Flagon stone, stands adjacent to the castle remains, indicating the site's significance extending back into the Bronze Age or earlier.
Harry's Walls unfinished 16th century artillery castle and adjacent prehistoric standing stone at Mount Flagon, St Mary's is a scheduled monument protected by Historic England under reference 1013274. View the official record →
Harry's Walls is an unfinished 16th century artillery fortress located on the Isles of Scilly off the coast of Cornwall. It is designated a Scheduled Ancient Monument by Historic England (NHLE) under reference 1013274.
Harry's Walls unfinished 16th century artillery castle and adjacent prehistoric standing stone at Mount Flagon, St Mary's is a Scheduled Ancient Monument, legally protected by Historic England (NHLE) — the body responsible for designating and safeguarding heritage sites in England. The official designation reference is 1013274.
Several scheduled monuments lie within 10 km, including Kerbed platform cairn on Wingletang Down, 80m north east of Porth Askin (4.4 km), Nineteenth century gig-shed north east of Porth Askin (4.4 km), Two 19th century gig-sheds ENE of Porth Askin (4.4 km).
This page is just one thread. A full Aubrey report pulls together 15 strands of Harry's Walls unfinished 16th century artillery castle and adjacent prehistoric standing stone at Mount Flagon, St Mary's's history, each drawn from the record and mapped to the exact spot:
Every location is different. Not every section appears for every place, only what the historical record actually holds turns up in a report.
Harry's Walls unfinished 16th century artillery castle and adjacent prehistoric standing stone at Mount Flagon, St Mary's stands on Unnamed Igneous Intrusion, Carboniferous To Permian, bedrock that formed in the Permian. The rock here is felsic-rock.