Blackrock Castle is a fortification located outside Cork city centre on the banks of the River Lee. It was originally built at a request by the citizens of Cork to Quen Elizabeth I as a coastal defence fortification in the 16th century to protect upper Cork Harbour and port, to “repel pirates and other invaders”. It is the oldest surviving structure still in use in the city of Cork. This historic castle has served as an Admiralty Court, a lighthouse, a signalling station and a gun battery, defending the river approach to Cork. The earliest elements of this structure remaining today are a circular tower on the water’s edge.
In 1722 the old four storey tower was destroyed by fire, Following a banquet, the castle was destroyed by fire in 1827. It was rebuilt in 1828 and was completed in March 1829.
In the early2000s, Blackrock Castle was redeveloped as an observatory
