The Pöstlingbergbahn is a narrow-gauge electric railway, or "mountain tramway", in Linz. It connects the main square in the centre of Linz with the district of Pöstlingberg, located at the top of a hill (or small mountain) at the northern end of the city. Opened in 1898, for 110 years the metre-gauge railway ran from a terminal station in Linz's Urfahr neighbourhood, located across from the terminus of urban tram route 3, to Pöstlingberg. In 2009, service was extended from Urfahr to the city centre. To permit this change, the railway was regauged from 1,000 mm (3 ft 3 3⁄8 in) metre gauge to 900 mm (2 ft 11 7⁄16 in) and a track connection to the Linz tram network was built. Service was suspended from March 2008 until May 2009 for this work. With a maximum grade of 11.6%, the Pöstlingbergbahn is one of the steepest adhesion railways in the world. There are steeper grades on at least one other tram system, that of Lisbon, but the Pöstlingbergbahn is still among the world's steepest adhesion railways and has the steepest grade of any in Austria.