You cannot stop a cat from exploring its world, and it would be cruel to try.
However, they are less likely to disappear if:
They are happy and secure at home, with plenty of toys and stimulation. Some cats get lost after a house move, which can be stressful for them.
Have they been neutered? Unneutered tom cats tend to roam over a wide area looking for females and are more likely to get lost, as well as get into fights and be injured or even killed on the roads.
Are they micro chipped or at least wearing a quick-release safety collar with your phone number on?
Neighbours know the animal belongs to you.