 Settlements grew up around both castles on the Medina , but East Cowes Castle was rapidly abandoned and ultimately destroyed by coastal erosion ; as a result , today West Cowes Castle is often simply referred to as Cowes Castle . Inspections in 1547 showed that there were 17 iron and brass artillery pieces at the fort , but that nine of these were inoperable ; nonetheless it continued in use as a fortification after the original invasion scare had ended , staffed with a garrison of a captain , porter and three gunners during Queen Elizabeth 's reign . 
