Ubud is typically as far north as most visitors to Bali ever reach though it is still, geographically and culturally, in the south. The older communities in the mountains still adhere to strict social customs, some retain their own dialects, and many remain wary of visitors and interlopers. They may pay lip service to tourists and embrace the compensations they bring, but they are not necessarily adapting to their visitors' customs.
The central mountains remain important to all Balinese, as the mountains are the homes of their gods. Therefore, this region is a spiritual center and place of pilgrimage, where temples and their celebrations abound. Water from here is the source of much of the irrigation for rice in the south, which enhances the mountains' revered place in the hearts of the Balinese. You will see many temples devoted simply to the water goddess Dewi Danu.
You will need a car, a driver who can also translate, a map, some walking shoes, and a plan. And don't forget your sarong.