Industry as a Determining Factor of Sustainable Development of Settlements by the Danube

The success of a city has always been largely determined by its ability to provide jobs for its inhabitants. The essential in this process is its location - determining the relationship between a city and the main transport routes. A special category in this context presents port cities Thanks to their strategic location, port cities have become the focus of trade, crafts and production. The water transport network was a key impulse for the development of industrial towns of the 19th and 20th centuries, allowing these areas to boom their industry sector. With its downturn and the shift of economic focus to the tertiary and quaternary sectors by the end of the 20th century, much of the industrial heritage today remains unused and it has been deteriorating. Saving this industrial heritage today presents a great opportunity for new developments that could be driven by a more sustainable direction and more sensitive urban development interventions. Within the European context, the most significant element has been the Danube - a strong geographical determinant that has influenced industrial development. Its catchment area reaches the territory of eighteen states and directly flows through ten or forms the state border. It thus becomes the most international river in the world with significant potential, economic, cultural and natural as well. The most important current discussions on a sustainable urban development deal with restructuring industrial areas and reworking the Danube riverbank. Researches approach this complex issue by analyzing the changing relationships among the river, city and industry. This paper focuses on case studies of three cities from different countries (Komarno - Slovakia, Obuda - Hungary, Galati - Romania), which combine similar social, economic and political developments. Paper introduces natural development and transformation of industrial sites in relation to the Danube and their impact on urban development while mapping its further potential. The similarity of the port cities by the Danube is not accidental. Historical developments and specific events have had an impact on the position of city ports and shipyards, whether preserved in the form of industrial heritage, stagnant or functioning industry, continue to have a high share of urban development. These sites are advantageous not only for their geographical location, but also for their tangible and intangible cultural heritage. In the discussion, the paper combines findings of the overall transformation of settlements in a post-socialist context with industrialization tendencies and local specific factors such as peripheral and historical events. The article deals with the importance of temporary or permanent urban and architectural solutions for improving the attractiveness of the river environment, promoting historical industrial identity, enhancing ecological mobility and, in particular, integrating the whole Danube region into everyday life. Finally, the current needs of finding environmental solutions for industry and transport in the context of sustainable urban development are discussed. The environmental program of industrial and commercial development based on the strategic planning of urban development is the foundation of the prosperity of the urban society.