The only type of settlement known in Galicia during the Iron Age are forts and fortified towns (castros) built in hills and peninsulas.
A series of place-names have been attributed to them:[71] There also existed a village called Bretonos near the city of Lugo, in the Middle Ages.
The most frequent element among the Celtic toponyms of Galicia[4] is *brigs,[107] meaning 'hill, high place', and by extension 'hillfort'.
Usually it is the second element in composite toponyms ending in -bre, -be or -ve,[108] being cognate of Irish Gaelic brí 'hill', with the same origin: Proto-Celtic *-brigs > -brixs > -bris.
Some of these toponyms are:[109] Another frequent type of Celtic toponyms in Galicia are those whose names are formed as a superlative,[152] either formed with the suffix -mmo- or with the composite one -is-mmo-: Other villages and parishes have names with pre-Latin, probably Celtic, origin, specially in the coastal areas of A Coruña and Pontevedra provinces and all along the valley of the Ulla river.