Families that are looking for specific activities will find many things that they can do. Fishing, golf, and horse riding are the things most widely available and can be found both within the National Park itself as well as in the northern coastal areas. Naturally, the central focus of your stay here is probably going to be Snowdonia.
Mount Snowden itself is a mountain you should climb purely for the sense of achievement having done so, the views and everything else you experience while doing it are simply a bonus. However, if you do not feel particularly energetic, you can take the train to the summit, which only takes part of the day and leaves you free to follow other pursuits.
In addition to the activities already mentioned, Snowdonia is filled with a range of walking and cycling routes, while climbing and abseiling is widely offered at various points throughout the surrounding area. Harlech Castle is more of a drive from Bala, but is a UNESCO World Heritage Site and part of the coastline you should not miss of given the opportunity to visit.
Bala is your ideal gateway to the rest of Wales, offering a peaceful place to stay with much to see on your doorstep.