The Fortress of Seven Towers/Yedikule is a fortified part of the original Byzantine walls. The Ottomans used it as a prison. Turkish nobles and commoners were held here as well. Important foreigner prisoners were held here. Yedikule was the prison of hundreds of Hungarians. TThe most notable examples, Mihály Szilágyi (1460) and Gergely Bornemissza (1555), were both executed here. The last Hungarian held here between 1698-99 was Count Antal Esterházy, who carved his name in the walls. He was later part of the Rákóczi immigration. Historians dispute whether Bálint Török was held here – he was more possibly kept under better conditions in home guard. Bálint Török still has a memorial plate at the Yedikule because of the tradition developed by writer Géza Gárdonyi. Unfortunately, the building currently is not open to visitors.