Vang Vieng is a city that is all about the outdoors. 

To be honest, when I went there the first time, I was a bit disappointed about the city activities. There's very little to do during the day in the city. There are a few restaurants and that's really about it. 

However, if you rent a scooter you'll have a lot better time. The city is all about exploring, hiking, trails, natural springs, and night markets. 

I would recommend the Thai restaurant and the Italian pizzeria.