In modern times, this Byzantine fortress—its name means "the seven towers"—was an abysmal prison, closed only in 1988. There's not much to see here except wall ruins and a small museum that documents the building's history. The area is an untended green space, not an unpleasant place to sit and survey Thessaloniki below. The surrounding tavernas accommodate throngs of locals in the evening.
- Address: Eptapyrghiou, Ano Polis, Thessaloniki
- Phone: 2310/310400; 2310/331040
- Hours: Tues.–Sun. 8:30–3
- Location: Ano Polis to Aristotelous Square