Brownsea Castle the castle also has four cannons, probably dating from the 17th or early 18th century. The castle is protected under UK law as a Grade II listed building. Brownsea Castle Brownsea Castle, also known historically as Branksea Castle, was originally a Device Fort constructed by Henry VIII between 1545 and 1547 to protect Poole Harbour in Dorset, England, from the threat of French attack. Located on Brownsea Island, it comprised a stone blockhouse with a hexagonal gun platform. It was garrisoned by the local town with six soldiers and armed with eight artillery pieces. The castle remained in use after
Brownsea Island Scout camp National Trust. She planted a mulberry tree to mark the occasion. The Trust has continuously maintained the island since then as a conservation area. In 1964, near the original campsite were set aside for Scout and Guide camping. In 1973, a Jamboree was held on the island for 600 Scouts from seven nations, along with one of the original campers, then aged 81. The National Trust maintains the Scout and Guide campsite, South Shore Lodge and the Baden-Powell Outdoor Centre where members of Brownsea Island Scout Fellowship and Friends of Guiding operate a small trading post. The Baden-Powell Outdoor Centre