Silly (Dutch: Opzullik) is a Walloon municipality located in the Belgian province of Hainaut. On January 1, 2006 Silly had a total population of 7,995. The total area is 67.68 square kilometres (26.13 sq mi) which gives a population density of 118 inhabitants per km².
The name of the town derives from its stream, called the Sille (French) or Zulle (Dutch), and has no relation to the English word.
Twin towns – Sister cities
Silly is twinned with: