Kastama is a toponym found in the archives of Hattusa. In KUB XVII 21 II, it appears in a 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 nearby town.
The geographical proximity and the phonetic verisimilitude are the only criteria to say that Kastama is Kastamonu. Even if no link appears in the Hittites 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 at the origin of the Hittite name of this town:
My notes of veracity :
Kastama is the Hittite name of the present city of Kastamonu: 3/5