Swiss regional nature parks are intended to be model regions for sustainable regional development in rural areas. It is often claimed that achieving sustainable development requires a transformation. One approach whereby parks could foster this is through transformative learning (TL). This article discusses attachment development (AD) of local people to a park from the perspective of TL. AD and TL have many similarities, and a transformation can be achieved through AD. Furthermore, TL theory offers a theoretical concept for explaining characteristics of AD. Several essential aspects have to be secured: an initial “emptiness” is needed as a “disorienting dilemma” to start the process. Further, there must be enough time and openness for processes and results. If these aspects are given, AD not only enables a transformation, but also increases the park's success.