The best way to explore the valleys is on foot. This can be done on your own or with a guide. There are several advantages to going with a guide. The maps available are a bit difficult to follow at times, and many people find themselves back-tracking to find the right trail.
However, one of the main reasons to hire a walking guide is their knowledge of all of the treasures hidden in the valleys. On your own you may walk past a beautiful church or an ancient dwelling without noticing it, and you will miss out on an opportunity to learn more about the region and its history.