Stuttgart 21 is a railway and urban development project in Stuttgart, Germany. It is a part of the Stuttgart–Augsburg new and upgraded railway and the Magistrale for Europe (Paris—Vienna) in the framework of the Trans-European Networks. Its core is a renewed Stuttgart Hauptbahnhof, amongst some 57 km of new railways, including some 30 km of tunnels and 25 km of high-speed lines.The project was officially announced in April 1994. Construction work began on 2 February 2010.