castle castle castle cornwall built approximately response fears invasion england france shaped stone fortification equipped gun ports cannon overlooked mouth cornwall protected curtain wall surrounding cliffs castle remained use years closed end napoleonic wars brought service war fitted new artillery positions soon obsolete abandoned second world war castle house battery naval guns protecting coast threat german attack end conflict castle restored previous condition managed english_heritage tourist attraction history construction castle built consequence international tensions england france final years reign king henry viii traditionally crown left coastal defences local lords communities taking modest role building maintaining fortifications france empire remained conflict maritime raids common actual invasion england unlikely modest defences based simple towers existed south west sussex coast impressive works north england general fortifications limited scale henry broke order long standing marriage catherine catherine aunt took personal insult resulted france empire declaring alliance henry pope encouraging countries attack england invasion england appeared certain henry began improve coastal defences response situation small shaped stone fortification built protect cornwall important centre trade harbour reached estuary local town protected previous century positioned river edge boom chain new castle replaced located high overlooking entrance estuary point took construction work began castle point direction member local gentry map local defences described castle half antiquarian visited described hosted recorded construction funded partly partly local town later use castle remained use years english civil war held royalist supporters king charles parliament local reported fortification state antiquarian visited castle noted fortification maintained expense local town praised picturesque romantic position concluded building little importance antiquity architecture time castle equipped cannons continued battery end napoleonic wars war broke fresh concerns invasion raised coastline castle redeveloped work new gun positions built old castle equipped pound rifled muzzle loading artillery pieces supported volunteer forces training purposes weaponry obsolete site fallen use end century castle brought use second world war defend coast german attack june equipped gun battery observation post additional concrete defences laid position inch naval guns installed 19th century firing positions new gun position built metres west castle supplemented french millimetre gun old control minefield estuary guns manned battery battery retired active operations november entire fort decommissioned newer defences removed 21st century castle operated heritage organisation english_heritage tourist attraction protected law grade listed building scheduled monument architecture 16th century storey shaped design metres internally walls slate rubble metres thick resting platform cut bedrock ground floor originally semi circular gun ports overlooking sea estuary blocked floor gun ports filled smaller windows smaller gunpowder weapons building fireplace chimney small guard chamber entrance topped walk sea estuary position rocky surrounded cliffs curtain wall semi circular area square metres size incorporating slits firing muskets rectangular metres internally metres thick walls protects rear original blocked later work current steps building 19th century origin flat magazine cut rock 19th century gun platform circular gun carriage rails constructed protected granite curtain wall reworked period marked plaques labelled marks additional defences second war seen places gun platform
St Catherine's Castle