Short distances
In Belgium, there are always a lot of different things nearby. In other countries, you often need to travel for two hours just to see something else. And then your kids have already reached their limit before you get there.
In Belgium, you can see a lot of different things (e.g. nature, small towns, amusement parks …) in half an hour of travel time. And then your kids still have some energy left when you get there.
Places to visit
There are a lot of small towns in Belgium with medieval buildings that look knightly or princessy. They are not overcrowded, so you won’t constantly have to look for your children.
These small towns often organize activities for kids (e.g. scavenger hunts), but they often only have documentation in the local language (Dutch or French). But check with the local tourism center, because sometimes they have it in English or it is still translatable.
The larger cities (e.g. Antwerp, Brussels, Ghent) have activities for children available in other languages, but these cities are not ideal for visiting with young children. There are too many people and it can be very busy.
Belgium also has a lot of castles. And forests where you have a zone where children can play freely (called a ‘speelbos’).
Restaurants
Most restaurants have a menu for children. These meals are smaller and cheaper.
Outside the city, you have many restaurants that have a playground (speeltuin in Dutch, ‘espace de jeux extérieurs’ in French). You can get your entree while your children have their main course. You can then afterward eat your main course in peace, while they play. And if they have behaved, they can have dessert as well.