Using Germany’s southwest as a case study, we explored how (cultural) landscapes have evolved over time and what the corresponding instruments are that have been put in place to maintain and develop them. Two main types of legal nature conservation and landscape management instruments safeguard cultural landscapes and landscape elements. These are the protected site system, including several protected area categories, and landscape management through landscape planning and the impact mitigation regulation. However, based on the recognition that cultural landscapes and landscapes elements can only be sustained and maintained as living cultural landscapes in the long term, if they are used and valued for the multiple functions and services they provide, new voluntary instruments have been introduced at the beginning of the 21st century. The PLENUM strategy, one of the voluntary instruments that has been introduced in Baden-Wu¨rttemberg to complement the legal instruments, has the potential to contribute to the sustainable development of cultural landscapes into the future by re-establishing traditional land uses, and accommodating new uses based on emerging needs. However, regional development strategies, such as PLENUM, if not well governed and implemented bear significant risks. They may advantage economic sectors, entrepreneurs and elites in pursuing their private gains rather than the common good. Therefore, we recommend that, although no panacea, regional development strategies need to be embedded in legal landscape planning frameworks. This means that cultural landscape development, whether in Germany, Europe or elsewhere, requires environmental legislation that restricts and compensates for adverse environmental effects from development projects, and genuine innovative strategies that support sustainable regional development from the bottom-up. PLENUM, as a project and governance approach, needs to prove itself as a genuine forward-looking model that achieves ‘‘protection via use’’. Application in diverse landscapes and legal contexts will contribute to this effort. The transdisciplinary approaches offered by sustainability science will, on one hand, inform and support such applications, and on the other hand, such applications will have the potential to contribute to the transformational agenda of sustainability science (Lang et al. 2012).