Line C () is a line on the Prague Metro. It crosses the right-bank half of the city center in the north-south directions and turns to the east at both ends of the line. It is the system's oldest and most used line, being opened in 1974 and transporting roughly 26,900 persons per hour in the peak. The line is long and includes 20 stations, journey from one end to the other taking approx. 35 min. History Segment I.C Construction was started in 1966 on an underground rapid tram line. One year later, the project was changed to a metro line. This segment, leading from Florenc to Kačerov, was opened on May 9, 1974. It is long and includes 9 stations and a train depot at Kačerov. It is mostly built using cut-and-cover technology, except for bored tunnels around the Pankrác station and crossing of the Nusle valley inside the Nusle Bridge. Between the Muzeum and Hlavní nádraží stations is the shortest distance in the system (ca. 400 m). Interior of the stations on this segment is made mostly using marble blocks, the main exceptions being Vyšehrad with large glass windows and Budějovická with limestone blocks. Segment II.C In 1975 commenced the construction of the second segment, going from Kačerov to large housing estates in the southern parts of the city. It is long and includes five stations. Interior decoration consists mostly of ceramic tiles, except the end station Háje, using limestone blocks and aluminium tiles. Segment III.C The third segment, connecting Holešovice district with the city center, was opened in 1984. It is long and includes two stations. Its stations are decorated by ceramic tiles similar to the second segment, but here they are larger. Segment IV.C The fourth segment is the only one in the history of Prague metro, which has been divided into two construction segments Segment IV.C1 The segment IV.C1, opened in 2004, extends from Nádraží Holešovice to the temporary terminus Ládví. It is long and contains two stations. Construction of this segment, which began in 2000, is perhaps the most difficult in the history of the Metro. Unique technology was used in constructing the tunnel under the river Vltava: The concrete tunnel tubes were made in a dry dock on the shore, the riverbed was excavated and the tubes were then laid down into the pits. The tunnels were due to the elimination of the