Sürmene (Humurgan)[5] is situated some 40 km (25 mi) east of Trabzon. Known in antiquity also as Susarmia or Augustopolis,[citation needed] it lies on the River Kora (Manahoz Deresi) and is best known as the place where Xenophon and his Ten Thousand fell sick after eating wild honey, an event which was confirmed by the local people. In the village of Kastil, 5 km (3.1 mi) to the west of Sürmene, stands a ruined medieval castle as well as the impressively restored 18th-century Yakupoğlu Memiş Ağa Konağı mansion. This was formerly the seat of the Yakupoğlu family, who lived here as rulers (derebeys, hence its alternative name of Derebeyli Kale, the Castle of the Derebeys) of the surrounding region relatively free of interference from the Ottoman government in faraway Constantinople/Istanbul.
