The futuristic mosque, which is being built under the auspices of the Ditib Turkish association, will have a large dome and two 55-metre minarets. Critics of the project say they will spoil Cologne's skyline by taking attention away from the city's famous Gothic cathedral.
“We're not just laying a cornerstone for a mosque and community centre,” said Ditb spokeswoman Ayse Aydin according to public broadcaster WDR, “We're also laying here a cornerstone for our common future.”
The debate over the mosque's construction has come to symbolise the conflict between Europe's growing Muslim population and those who believe Muslim immigration to the continent should be curtailed. Plans for the mosque have drawn protesters from around Germany and Europe, including right-wing extremists. One such planned rally was canceled by police for fears of violent protests.
To avoid inflaming public sentiment against the project, Ditib agreed to not broadcast the call to prayer to the neighbourhood from the minarets and to keep the building's height the same as nearby structures.
When completed in two years, the mosque will hold between 2,000 to 4,000 worshipers and replace a series of ad-hoc places of worship that have developed around the city as Cologne's Muslim population grew.
At the event, Cologne's former mayor Fritz Schramma described the mosque's architecture as “a symbol of an opening blossom, that invites you to peek inside.”