the city was confined to West Berlin up till and including 1989. Beginning in 1990 the course was re-routed into part of East Berlin, and in 2001 a further adjustment meant that the course has since run through Potsdamer Platz. Typically the leaders will pass through the platz about ten minutes before they cross the finish line. Another annual tradition that began in West Berlin (in 1952) and was re-routed into the east via Potsdamer Platz following German reunification is the Weihnachtszug (Christmas train). It now does a regular two-hour round trip at weekends in the run-up to Christmas for families with children, starting and finishing at the Potsdamer Platz S-Bahn station. It did not run in 2009 or 2010 due to equipment problems, but is expected to be operational again in 2011. Europe's largest building site After 1990, the square became the focus of attention again, as a large (some 60 hectares), attractive location which had suddenly become available in the centre of a major European city. A lot of more than at Potsdamer Platz had been acquired by Daimler-Benz in 1987 as an expression of faith in Berlin; in 1990, adjacent plots were bought by Sony and the ABB Group. The area was widely seen as one of the hottest, most exciting building sites in Europe, and the subject of much debate amongst architects and planners. If Berlin needed to re-establish itself on the world stage, then Potsdamer Platz was one of the key areas where the city had an opportunity to express itself. More than just a building site, Potsdamer Platz was a statement of intent. In particular, due to its location straddling the erstwhile border between east and west, it was widely perceived as a "linking element," reconnecting the two-halves of the city in a way that was symbolic as well as physical, helping to heal the historical wounds by providing an exciting new mecca attracting Berliners from both sides of the former divide. Whether fairly or unfairly, a great deal was riding on the project, and expectations were high. The Berlin Senate (city government) organised a design competition for the redevelopment of Potsdamer Platz and much of the surrounding area. Eventually attracting 17 entrants, a winning design was announced in October 1991, that from the Munich-based architectural firm of Hilmer & Sattler. They had to fight off some stiff competition though, including a last-minute entry