Wikipedia
Zalpuwa, also Zalpa, was an as-yet undiscovered Bronze Age Anatolian city of ca. the 17th century BC. Its history is largely known from the Proclamation of Anitta, CTH 1.
Zalpuwa was by a "Sea of Zalpa". It was the setting for an ancient legend about the Queen of Kanesh, which was either composed in or translated into the Hurrian language:
[The Queen] of Kanesh once bore thirty sons in a single year. She said: "What a horde is this which I have born[e]!" She caulked(?) baskets with dung, put her sons in them, and launched them in the river. The river carried them down to the sea at the land of Zalpuwa. Then the gods took them up out of the sea and reared them. When some years had passed, the queen again gave birth, this time to thirty daughters. This time she herself reared them. 1
The river at Kanesh (Sarımsaklı Çayı) drains into the Black Sea, not (for example) Lake Tuz. "Zalpuwa" is further mentioned alongside Nerik in Arnuwanda I's prayer. Nerik was a Hattic language speaking city which had fallen to the Kaskians by Arnuwanda's time. This portion of the prayer also mentioned Kammama, which was Kaskian as of the reign of Arnuwanda II. The best conclusion is that Zalpuwa was in a region of Hattian cities of northern central Anatolia: as were Nerik, Hattusa, and probably Sapinuwa. Zalpuwa was most likely, like its neighbours, founded by Hattians.
Ca. the 17th century BC, Uhna the king of Zalpuwa invaded Neša, after which the Zalpuwans carried off the city's "Sius" idol. Under Huzziya's reign, the king of Neša, Anitta, invaded Zalpuwa. Anitta took Huzziya captive, and recovered the Sius idol for Neša. Soon after that, Zalpuwa seems to have become culturally Hittite and Nesian-speaking.
Arnuwanda's prayer implies that Zalpuwa was laid waste by Kaskians, at the same time that Nerik fell to them, in the early 14th century BC.
İkiztepe on the Kızılırmak Delta near the Black Sea coast is suggested as a possible location for Zalpuwa.