In 1990 a centuries-old tradition of beer brewing returned to the Oudegracht after 93 years of silence, when the Utrecht City Brewery settled in the vaults of City Castle Oudaen. While the Oudaen belongs to the world’s smaller breweries, it's a modern business and about 75,000 litres of beer are produced here each year. The only steam brewery in Utrecht is situated in one of the four underground vaults located beneath street level inside the castle.