Blackrock Castle

Blackrock Castle - Credit: Wikimedia Commons

Blackrock Castle is a castellated fortification located at Blackrock, about 2 km from Cork city centre on the banks of the River Lee in Ireland. Originally developed as a coastal defence fortification in the 16th century to protect upper Cork Harbour and port, the site now houses an observatory, visitor centre and restaurant. Read more on Wikipedia

type: military installation
date from: 1582

Source: en.wikipedia.org