overview about the place The Negrelli (Karlín) Viaduct is the second oldest bridge over the Vltava River in Prague and the oldest railway bridge in Prague. It is one of the most important technical structures in the city and with its length of 1110 m, it was indeed the longest bridge in Europe until 1910. The beginning of the viaduct is located in the Prague 1 district of Nové Město, continuing over the Florenc bus station, where it forms the border between Nové Město and Karlín, then through Karlín and across the Vltava island of Štvanice to the Holešovice district of Bubny. history The Negrelli Viaduct is the thirteenth bridge over the Vltava River in Prague (counted downstream). It is also the second oldest bridge in the city and the first ever railway bridge over the river. Its construction was necessary for the continuation of the Northern State Railway from Prague to Dresden. The viaduct connects Masaryk Station and Bubny and separates Nové Město from Karlín. Until 1910, it was actually the longest bridge in Europe. Its length is 1110 m, while the original width of the bridge deck is 7.60 m, and a full 9 m after removal of the stone parapet. The railway line was double-tracked. The bridge was built in 1846—49 by renowned Austrian transport engineer Alois Negrelli, who also contributed to the planning of the Suez Canal and regulated the Rhine and several other Czech rivers, as evidenced by his aristocratic predicate von Mold-Elbe (Alois Negrelli von Mold-Elbe). The famous Czech builder Jan Perner also participated in the construction of the viaduct. The bridge originally had 87 arches, eight of which stood directly in the Vltava River. Construction was assigned to the partners Vojtěch Lann and the Klein brothers. At the time, 3,000 workers of various nationalities worked on the bridge. Steam lifting machines were used to a greater extent for the first time ever during construction. Operation of the viaduct started on 6 April 1851. The entire viaduct had arches of block masonry made of Bohemian granite, and the pillar facings were made of sandstone with granite blocks on the corners. The core of the masonry is made of rubble stone, while the pillars are based on wooden grids. The purity and uniformity of the construction concept were broken up only during later reconstructions due to the ever-increasing demand for urban and railway transport. For instance, in the second half of the 19th century a third dead-end shunting track was laid and a new eastern track branch was built. In 1952—53, three arches over Křižíkova Street were removed and replaced with concrete beams, and in 1981 the same was repeated over Bubny Embankment. This was due to the construction of off-grade intersections for ever-expanding vehicular traffic. Nevertheless, the Negrelli Viaduct is proof that even a technical structure can boast a superior aesthetic level, which is why it is listed in the National List of Immovable Cultural Monuments. Reconstruction In 2017—2020 the viaduct was reconstructed along its entire length. All 100 arches were repaired, with eight of them spanning two arms of the Vltava River, five bridge structures over roads and two bridge structures dating from a later period were replaced (the first spanned Prvního pluku Street, the second Křižíkova Street) and fourteen arches were completely rebuilt.