''Line 3'' (Blue Line) runs from Nikaia station, through the central Monastiraki and Syntagma stations to Doukissis Plakentias avenue in the northeastern suburb of Halandri. It then ascends to ground level and continues to Athens International Airport Eleftherios Venizelos using the suburban railway infrastructure, extending its total length to . The spring 2007 extension from Monastiraki westwards to Egaleo connected some of the main night life hubs of the city, namely those of Gazi (Kerameikos station) with Psirri (Monastiraki station) and the city centre (Syntagma station). Extensions are under construction to the western and southwestern suburbs of Athens, as far as the Port of Piraeus. The new stations will be Maniatika, Piraeus and Dimotiko Theatro, and the completed extension will be ready in 2022, connecting the biggest port of Greece, the Port of Piraeus, with Athens International Airport, the biggest airport of Greece.