Work has begun this week in preparation for the construction of a totally new metro line that will run between Maroussi in northern Athens and the Veikou woods near Galatsi but will also pass through neighborhoods such as Kolonaki in the city center. It was revealed yesterday that civil engineers have begun testing the ground in various parts of the city to determine where the tunnels are to be dug. The preparatory work is due to be completed by the end of the year. The Environment and Public Works Ministry will then have to issue the final go-ahead for the project. Line 4, also known as the «U» line because of its shape, will be some 21 kilometers (13 miles)long and will have 20 stations that will include Filothei, Zografou, Pangrati, Exarchia and Kypseli. A time frame for the opening of the line has not been made public yet.