In 53 BC, Julius Caesar stated that the lands of the Dacians started on the eastern edge of the Hercynian Forest. This corresponds to the period between 82–44 BC, when the Dacian state reached its widest extent during the reign of King Burebista: in the west it may have extended as far as the middle Danube River valley in present-day Hungary, in the east and north to the Carpathians in present-day Slovakia and in the south to the lower Dniester valley in present-day south-western Ukraine and the western coast of the Black Sea as far as Appollonia. At that time, some scholars believe, the Dacians built a series of hill-forts at Zemplin (Slovakia), Mala Kopania (Ukraine), Oncești, Maramureș (Romania) and Solotvyno (Ukraine). The Zemplin settlement appears to belong to a Celto-Dacian horizon, as well as the river "Patissus" (Tisa)'s region, including its upper stretch, according to Shchukin (1989). According to Parducz (1956) Foltiny (1966), Dacian archaeological finds extend to the west of Dacia, and occur along both banks of the Tisza. Besides the possible incorporation of a part of Slovakia into the Dacian state of Burebista, there was also Geto-Dacian penetration of south-eastern Poland, according to Mielczarek (1989). The Polish linguist Milewski Tadeusz (1966 and 1969) suggests that in the southern regions of Poland appear names that are unusual in northern Poland, possibly related to Dacian or Illyrian names. On the grounds of these names, it has been argued that the region of the Carpathian and Tatra Mountains was inhabited by Dacian tribes linguistically related to the ancestors of modern Albanians.