Karaka fort
La Goulette, Tunisia · built 1535
The Fort of La Goulette (also known as the Karraka) is a coastal fortress in La Goulette, at the entrance of the Lake of Tunis. It was built by the Spanish in 1535 after the conquest of Tunis by Charles V, to secure access to the city and the lagoon. The Ottomans captured it in 1574, and the site was later reused as a prison during the 19th century, which explains the popular Tunisian use of the word Karraka to mean "penitentiary".
Prison data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).