The site of Büklükale - Twisted Castle, also referred as Kapalıkaya, Büyükkale, or Büyukkaletepe, is located on the western bank of the Kızılırmak, opposite the village of Köprüköy in Kırıkkale Province.
See:
- Joost Blasweiler, The cities Turmitta and Wahšušana along the banks of the Kizilirmak?, Arnhem (nl) 2019 - 1 Anatolia in the Bronze Age
- Mark Weeden, A Hittite Tablet from Büklükale, London, AAS XVIII 2013 - https://eprints.soas.ac.uk/18265/1/Weeden%2C%20BKT1%2C%20AAS%2018%20%282014%29.pdf
- Gojko Barjamovic, Sites, Routes and Historical Geography in Central Anatolia. in ipamati kistamati pari tumatimis. Luwian and Hittite Studies Presented to J. David Hawkins on the Occasion of his 70th Birthday, ed. I. Singer. Tel Aviv: Emery and Claire Yass Publications in Archaeology., Pp. 10-25