This study examines the processes of deterioration affecting disused railway buildings, their architectural significance, and the possibilities of adaptive reuse. While the notion of “ruins” is commonly associated with romantic remnants of ancient or medieval structures, contemporary landscapes increasingly feature modern ruins linked to obsolete railway infrastructure. The Hungarian railway network was largely developed during the second half of the nineteenth century, within the framework of the Austro-Hungarian Monarchy, and underwent significant expansion during the twentieth century, particularly in the post-Second World War decades. However, technological changes in railway operation, transformations in freight transport, and evolving travel habits have rendered a substantial portion of the building stock functionally obsolete. Functional obsolescence constitutes the first step towards ruination: once a building falls out of use, maintenance ceases and material decay begins, progressing – depending on structural and climatic conditions – towards a conventional state of ruin. In the case of railway architecture, deterioration often affects not only individual buildings but entire station areas and operational complexes, resulting in extensive brownfield enclaves within the urban fabric. These areas frequently exert negative economic and social impacts on their surroundings, yet at the same time represent significant and largely untapped development potential. The paper reviews the architectural-historical significance and heritage protection status of Hungarian railway buildings, highlighting the relatively strong representation of late nineteenth-century historicist station buildings in the historic building register, while drawing attention to the insufficient protection of many high-quality examples of post-war modern railway architecture. International and domestic examples – including the High Line in New York and the Viaduc des Arts in Paris – demonstrate how the adaptive reuse of abandoned linear infrastructure and station buildings can generate new urban identities and contribute to the reconnection of fragmented urban fabric. The future of railway buildings lies in the coordinated application of documen tation, conscious heritage protection, and industrial heritage-based adaptive reuse. Regular maintenance, careful designation of architecturally valuable structures, and the identification of viable new functions are essential if modern ruins are to become starting points for regeneration rather than symbols of irreversible decline.