The Red Tower is Alanya's most recognisable landmark and one of the finest surviving examples of medieval Islamic military architecture in Turkey. Built in 1226 by the Seljuk sultan Alaeddin Keykubad I — the same sultan who developed the castle above — it is an octagonal five-storey tower rising 33 metres above the old harbour. The name comes from the distinctive reddish bricks used in its construction.
The tower was designed to defend the harbour and the shipyard (tersane) directly behind it. Its unusual octagonal plan was practical: the shape eliminated the blind corners that rectangular towers left for attackers to exploit. Each storey has its own water cistern, allowing the garrison to hold out independently if lower floors were breached.
Inside, the tower has been restored and houses a small ethnographic museum, with displays of local costumes and household objects. The upper galleries give excellent views across the harbour and back up toward the castle. The ground-floor cistern, with its arched stone vaults, is worth a look.