Signal Iduna Park, before 2005 called Westfalenstadion, was built to serve as a playing venue for the 1974 World Cup.
Until then Dortmund had played their home matches at Stadion Rote Erde, and while an expansion of that stadium was first considered, in the end was chosen to build a new stadium all together.
Westfalenstadion officially opened on the 2nd of April 1974 with a friendly between Dortmund and Schalke 04. The stadium back then only consisted of one tier that could hold 54,000 spectators, of which 37,000 standing. The stadium stood out because of its rectangular shape in a time when most large stadiums were still bowl-shaped, and its four separate stands served as inspiration for a new generation of stadiums. Ibrox Stadium‘s redevelopment in the late 1970s was, for example, largely based on Westfalenstadion.
The stadium remained largely unchanged until the early 1990s, when the increased successes of Dortmund grew the need for expansion. Works started with the conversion of part of the standing areas into seats, actually reducing capacity, but then continued in 1995 with the construction of a second tier on top of the East and West Stand. Shortly after, building works started on a second tier for the North and South Stand, which were completed in 1999. The stadium could then hold 68,600 spectators, and the 25,000-capacity South Stand had become the largest terrace of Europe.
In 2001, The redevelopment of the stadium was completed between 2002 and 2003 when all four corners got closed up with stands. Two years later, in 2005, the stadium changed name to Signal Iduna Park as a result of a sponsorship deal.
-During the 1974 World Cup, Westfalenstadion hosted three first round group matches and the second round group match between Holland and Brazil (2-0).
-In 2001, Westfalenstadion hosted the UEFA Cup final between Liverpool and Alavés (5-4).
-In 2006, Signal Iduna Park was one of the playing venues of the 2006 World Cup.
-Temporarily renamed and with a reduced capacity of 67,000 seats, the stadium hosted four group matches and the semi-final between Germany and Italy (0-2).