Remains of stone anchors from the second half of the 2nd millennium and the 1st millennium BC have been discovered in the waters around Primorsko, which can possibly be linked to
Neolithic navigation. Remains of lead anchors from the 4th-5th century BC have also been found, as well as traces of
Copper Age pottery and stone tools. Valchanovo kale, the ruins of a nearby medieval fortress, which inhabited from the
Early Iron Age to the
Late Middle Ages, are often linked with the fortress of Ranouli mentioned in the Hambarli inscription of
Krum of Bulgaria. Medieval
amphoras and pottery have been found in the mouth of the Ropotamo, and the ancient waystation and fortress of Gera is thought to have been located on Maslen nos.
Ottoman documents of the 16th century mention a locality called
Zonarita in the area. The eastern traveler
Evliya Çelebi marks a cove by the name of
Küprü liman at the place. During the Ottoman rule of Bulgaria, there existed a pier used to transport
Strandzha wood and charcoal to
Constantinople and other major cities. The modern Primorsko was founded in 1879 as
Kyupria by four families from
Zabernovo and
Balgari (who had left their villages after the
Berlin treaty left them in Turkey), who cleared the forest and built houses. In the vicinity were two abandoned
Circassian villages; the Circassians had fled to
Turkey fearing retribution for their atrocities in Bulgaria. Other Bulgarians from Central Strandzha came and briefly populated these villages but then decided that Kyupriya's pier is a better source of income and soon moved there, despite the danger of
malaria which Dyavolsko blato (Devil's Swamp) constituted. The town was renamed Primorsko in 1934. Primorsko was declared a national sea resort in 1953. In 1981, it was merged with
Kiten and became a town. In a 1998 local referendum, it split from
Tsarevo Municipality and became a seat of
Primorsko Municipality. One of the smaller towns in Bulgaria by population, Primorsko has seen a remarkable increase in residents in recent years, topping the list of Bulgarian towns by population growth between December 2004 and June 2005 with 13.5%. == Transportation ==