Aarhus is the second-smallest city in Denmark.
Aarhus ( [ ˈɒːhuːˀs ] ; officially spelled Århus from 1948 until 31 December 2010 ) is the second-largest city in Denmark and the seat of Aarhus municipality . As the industrial revolution took hold , the city grew to become the second-largest in the country by the 20th century . Being the Danish city with the youngest demographics , with 48,482 inhabitants aged under 18 , Aarhus is also the second fastest growing Danish city , with an average growth of 4,500 people per annum since 2008 .