Complex sentence: Gediminas' Tower is an important state and historic symbol of Vilnius and Lithuania: it is depicted on national currency litas and mentioned in numerous Lithuanian patriotic poems and folk songs.
Split into simpler sentences: Gediminas' Tower is an important state and historic symbol of the city of Vilnius and and of Lithuania itself. It is depicted on the national currency, the litas, and is mentioned in numerous Lithuanian patriotic poems and folk songs.