Famous architects, including Juraj Dalmatinac (best known for Šibenik Cathedral), were involved in the design and construction of Ston's extraordinary 14th-century defenses, which originally included 40 towers and five forts, and stretched for 7km. Twenty towers and 5.5km of wall are still standing, arching far up the hill between Ston and Mali Ston. You can walk the Ston section in 15 minutes; allow an extra 30 sweaty minutes to continue up and over the hill to Mali Ston.
Admission includes entry to the substantially reconstructed Fort St Jerome (Tvrđava sv Jeronima), a square castle with a tower at each corner positioned on Ston's southeastern flank.