Portugal has emphasized the significance of cultural and scenic touring in its tourism plans, positioning it as a strategic component of the national tourism offering. However, not all cultural heritage is leveraged for tourism, and there are several unique and relevant heritage elements that have been overlooked. The Castrejo heritage in northwestern Portugal is one such example, most of it being degraded and abandoned. This research has been carried out focusing the analyses of the touristic potential of the Castrejo heritage. Therefore, it was pertinent to understand its importance in the region’s history and to grasp the projects being undertaken to valorize this heritage, both in Portugal and Spain, specifically in Galicia. The results of this research confirmed that the Castrejo heritage in northwestern Portugal indeed possesses high tourism potential, despite its widespread state of neglect and degradation. It has the capacity to become an important tourism product for the region. The creation of tourism products based on this heritage aids in its preservation, promotion and valorization. As a result, at the end of the research, a proposal for a cultural tourism route called the “Rota dos Castros do Noroeste de Portugal” is presented.