The Belgrade tram system is a 1000 mm gauge network that in 2021 had 12 routes running on 43.5 kilometres (27.0 mi) of (at least mostly double) track in the city of Belgrade. It is operated with 231 trams, including ČKD Tatra KT4, CAF Urbos, and Duewag Be 4/6 trams. The first tram line was introduced on 14 October 1892. In the late 2000s, complete reconstruction of the system commenced.