The ''Old Blockhouse'' was a Tudor Era Fortification, located on The Isle of Scilly. It is also known to History as ''Dover Fort''. The structure is considered a ''Device Fort'' erected in 1548 to stem the possibility of French attack or invasion. The Fort is considered under the Regency of Edward VI (Heir presumptive to England's King Henry VIII). The Fortress was roughly a 23-foot Bastion Tower with a squared Top to support Artillery. The Perimeter walls that protected The Blockhouse were 3-foot high and 7-feet thick. A supportive earthen berm (9-feet thick) was erected in front of these walls. The Garrison Quarters were 12-foot by 9-foot.
Primarily, The Blockhouse was just that. A granite (4) side structure with wooden roof, attached to a circular bastion tower. Artillery was placed on the top of The Tower. A small defensive structure, typically only a (20) Man garrison could occupy the structure. With no French Invasion pending, The Blockhouse fell into disuse until The English Civil War of the 17th Century. The Blockhouse was garrisoned by Royalist supporters of King Charles I. In 1651, a Parliamentarian Naval Force attacked The Isle of Scilly and in particular The Old Blockhouse. Initially, the Landing Force was beaten back, but The Naval ships had Guns of Longer Range as as such, The Blockhouse could not defend itself. It was surrendered to Parliamentarian Forces.
By 1752, most of The Blockhouse had fallen into ruins, with it's artillery long since removed. In 1922 it was renovated and conserved as best as possible as a National Landmark.