Tilbury Fort Tilbury Fort is on the north , Essex , bank of the River Thames in England and was built to defend London from attack from the sea , particularly during the Spanish Armada and the Anglo - Dutch Wars . The site is now cared for by English Heritage and opened to the public . History . The first permanent fort at Tilbury was a D - shaped blockhouse built in 1539 by Henry VIII and first called the ' Thermitage Bulwark ' , because it was on the site of a hermitage dissolved in 1536 . The Tilbury blockhouse was designed to cross - fire with a similar structure at New Tavern , Gravesend . During the Armada campaign the fort was reinforced with earthworks and a palisade and there was a boom of ships ' masts , chains and cables stretched across from Thames to Gravesend anchored to lighters . Furthermore , it was in nearby West Tilbury that Elizabeth I rallied her makeshift army as it awaited the Armada in 1588 The fort was held for Parliament during the English Civil War and despite suffering from neglect was never attacked by the Royalists . In 1651 its garrison was a governor , a lieutenant , an ensign , four corporals , one drummer , a master gunner , 16 matrosses ( gunner ' s mates ) and 44 soldiers . After the English Civil war Charles II was exiled in Holland , where he was influenced by European advances in military architecture . Following the disastrous 1667 Dutch attack on the English fleet moored on the nearby Medway , Charles II set in motion the re - fortification of the site by employing Dutchman Sir Bernard de Gomme , who had been engineer in the Royalist army during the civil war and who followed Charles into exile . Work started on the current fort in 1670 but was conducted slowly , often with the use of pressed labour from nearby towns , and was still continuing in the 1680s . De Gomme ' s plan was for a pentagon with projecting bastions facing west , north west , north east and east and a planned river bastion facing directly south . Henry VIII ' s blockhouse was retained . Major features such as the imposing Water Gate were not complete until about 1682 . The river bastion never materialised . The resulting structure was " a nationally important example of angular bastioned defences and is the best preserved example " of de Gomme ' s work . Besides the brick fort , there was an earth and brick gunline along the river bank . In 1715 there were 31 demi - cannon and one culverin in the East Gun Line and 17 demi cannon and 26 culverins in the West Gun Line . Two huge powder magazines [ housing 3 , 600 barrels each ] were built in the centre of the fort in 1716 , but the same year many of the 161 guns surveyed were declared unserviceable and the effective strength was found to be just 60 pieces . In 1724 Daniel Defoe estimated there were 100 guns ranging from 24 - pounder to 46 - pounder : " A battery so terrible as well imports the consequence of the place " . There is a memorial to the Highland prisoners captured after the Battle of Culloden in 1746 who were held at Tilbury . A cricket match in 1776 between men from the Kent and Essex sides of the Thames allegedly ended in bloodshed when guns were seized from the guardroom ; it was reported that an Essex man was shot dead , an elderly invalid was bayonetted and a sergeant was shot trying to quell the riot , but this account is disputed . The Napoleonic invasion scare of 1803 saw the Royal Trinity House Volunteer Artillery manning 10 armed hulks across the Thames at Tilbury . Nineteenth century improvements in metallurgy and artillery firepower saw extensive re - design and re - modelling along the fort ' s riverside , much of it overseen by Captain Charles Gordon [ 1833 – 85 ] , later known as ' Chinese Gordon or Gordon of Khartoum ' . The 17th century walls were reinforced and earth was embanked on the outside to protect the brickwork from the effect of modern high velocity guns . Emplacements were built for 9 - inch muzzle - loader s on top of the bastions and these new works became the primary gunline angled more to the south - east to engage ships well downstream . The Henry VIII blockhouse was demolished around 1867 . The Victorian modernisation was , in due course , partly built over again prior to the First World War and it is these later concrete emplacements and expense magazines which visitors see today on the south - east curtain . The fort ' s sole military success was during the First World War , when anti - aircraft guns on the parade ground shot down a Zeppelin airship . Bombing damage in the Second World War destroyed the 18th century soldiers ' barrack block , but the officers ' terrace still survives . Demobilised in 1950 and placed in the care of the Ministry of Public Building and Works and opened to the public , the site is now cared for by English Heritage . The fort has several interesting features . The Water Gate , circa 1682 , is an ornate opening in the south wall allowing access to the quay on the river . The outer defences consist of two wet moat s , a ravelin and a redan . As a result of the 17th century rebuilding , part of the fort was in the parish of West Tilbury and part in the parish of Chadwell St Mary . The officers ' quarters were in West Tilbury and the other ranks ' quarters were in Chadwell . Consequently , officers that died were buried in West Tilbury and other ranks in Chadwell . Surrounding area . The fort lies between the World ' s End public house ( formerly the ferry house ) to the west and Bill Meroy Creek to the east . There is a separate fort at Coalhouse , East Tilbury , which has a Napoleonic and Victorian history . As part of the Tilbury Riverside project , a pathway has been developed between Coalhouse and Tilbury Fort passing along the river bank and past Tilbury Power Station . This is known as the Two Forts Way . The path is just over three miles and is described as " a challenging route suitable for able bodied walkers and experienced cyclists " .