Passage: The theme of Nicopolis, by the late 9th century, comprised the modern Greek prefecture of Aetolia-Acarnania and most of Epirus up to Buthrotum. In Late Antiquity, this corresponded to the province of Epirus vetus, but also included Aetolia, which was part of the province of Achaea. To the east, it bounded the theme of Hellas, probably along the river Mornos and the western slopes of the Pindus mountains, and to the north, with the theme of Dyrrhachium and the sclavinia of Vagenetia.

Question: Whats the last place mentioned?
Buthrotum