Kastama is a city name found in the archives of Hattusa. In KUB XVII 21 II, it appears in a named list of towns devastated by the Gasagas under Arnuwanda, towards the middle of the 2nd millennium BC: "Nerik, Hursama, Kastama, Serissa, Himuwa, Takkasta, Kammama, Zalpuwa, Kapiruha, Hurma , Dankusna, Tapasawa, Tarukka, Ilaluha, Zihhana, Sippiduwa, Washaya and Patalliya". Most of these cities are mentioned in another order in the same text: "Kastama, Taggasta, Serissa, Tastaressa, Takkupsa, Kammama, Zalpuwa and Nerik". Suppiluliuma, Mursili II and Hattusili III have conducted military campaigns at Kastama. The deified mount Zaliyanu has dominated this region. Himuwa was a near city.
The geographical proximity and the phonetic verisimilitude are the only criteria to say that Kastama is Kastamonu. Even if no link appears in the Hittite texts between Kastama and the country Tummana, it is likely that the city belonged to this country.
Traces of occupation from the early second millennium BC have been found in Kastamonu. The castle ( "Kalesi in Turkish) is probably the causing the Hittite name of this city: