Surmounting Alanya's rocky peninsula is its awesome, Seljuk-era castle, girdled by 6km of walls and awaiting Unesco World Heritage listing. Climb to it through the steep streets of the Tophane district to get a sense of its scale, enjoying a wonderful viewpoint across the city and Cilician mountains. Right at the top is the İç Kale, within which are plentiful ruins including some 400 cisterns, the shell of a small 11th-century Byzantine church and a platform over a vertiginous drop to the sea.
If you're not up to the steep 3.5km climb, catch bus 4 from the dolmuş station behind the Grand Bazaar (₺2.50, hourly from 9am to 7pm, half-hourly in summer) or opposite the regional tourist office (10 minutes past the hour and, in summer, also 15 minutes before the hour). Taxis are around ₺25. Alternatively, catch the new Alanya Teleferik, a cable car that ferries passengers between the lower station near Cleopatra’s Beach and the upper station in the castle's Ehmedek section.