Belgium is one of those countries with a lot to discover. Take their mountains for example.
Coming from a country with real mountains, I find the Belgian passion for Ardennes rather cute and I don't really have the heart to tell them that well... that they're just hills.
But the Ardennes are definitely worth visiting. They are in Wallonia, the French part of the country. You can get there quite easily with public transport but make sure you check beforehand the timetables of the local buses, especially if you're headed to a small village.
Like Gedinne - apart from two buses every weekday there is no other way to get there than by foot/car/hitchhiking.
The good thing about the Ardennes s is that you're surrounded by green hills and forests. If you head more towards the countryside, you're very likely to see more cows and sheep than people. What I like about them is that they are peaceful and relaxing, even in bad weather.
On a nice day, you can enjoy doing sports, from cycling or walking to canoeing. On the last note, there's only one river in Belgium where you can do canoeing and from what I've seen it's like a highway on weekends -busy and gets jammed often.
The little town village of Gedinne is surrounded by many little ponds and lakes, so on a sunny day, this is how your morning looks like.
Croix Scaille, the 9th highest mountain in Belgium (505 m) is less than 9 km away and quite a nice walk. There aren't many signs on the way, but if you stick to the main road, you should have no trouble getting there. On the top you can climb 50 m tower to enjoy the nice view of the valley (France and Belgium) and some tasty local beers.
As any small village, Gedinne too has its cute little quirks that make it worth visiting, from restaurants that serve food only during meal times to local bars and festivals that involve competition of plowing tractors. And of course adoring houses and gardens.
It's quite likely you will see everything Gedinne has to offer in one day. But to be honest, delicious food and nice people, makes it totally worth to stay an extra day..