Biržai is a city in northern Lithuania. Famous for its reconstructed Biržai Castle manor, the whole region is renowned for its many traditional-r…Biržai is a city in northern Lithuania. Famous for its reconstructed Biržai Castle manor, the whole region is renowned for its many traditional-recipe beer breweries. The exact origin of the city name is not known, but it is derived from the Lithuanian word beržas. The name of the city in other languages includes German: Birsen; Polish: Birże, Russian: Биржай ; Yiddish: בירז, Birzh. It is simplified to Birzai in English.