Everyone spontaneously thinks of “the market” when they think of the center of a municipality. Anyone who has ever visited an American city knows that this is usually not so obvious over there: where’s is “the center” of Los Angeles, San-Francisco, New York … ?
It becomes something completely different if you define the center as “the heart” of the city. Then you suddenly have a value judgment: the place that best represents the identity of a city. Then you can also have different “centers”: the center of power, the economic center, the entertainment center, …
You can also try to objectify the center. Then you usually end up at the geographical center of a municipality, a province, a country, a continent, etc. Here a search is documented for the geographical center of the 64 municipalities of the province of West Flanders.