Biologically active areas play an extremely important role in the structure of a city and increasing their coverage, especially in large urban centres, is an activity with a number of advantages. This article compares, in terms of green spaces, two European cities of similar size – Warsaw (517.2 km2) and Oslo (454 km2). Both cities are capitals of their respective countries but implement different spatial policies in the scope of the Green Deal. In Warsaw, many industrial and post-industrial areas still exist and simultaneously urban green areas are decreasing year by year. In Oslo, a strategy based on deindustrialisation of the city and possible maximum use of urban greenery and public spaces is implemented. The research described in this article involved analysing the coverage of the analysed cities and their districts with biologically active area and then checking the correlation with other indicators that can be affected by this coverage. These included data on the incidence of the most common diseases among residents, the attractiveness of living for the elderly and families with children, as well as air and soil pollution and the occurrence of negative effects of climate change. The correlation of urban space use in terms of the presence of industrial land in relation to currently existing green spaces in the districts concerned was subsequently determined.

The revitalisation of post-harbour and waterfront areas is an issue that has been subject to intensive public discussion over the recent years. The topic is becoming increasingly popular due to the high value of post-harbour areas. They are distinguished by their aesthetic, environmental and recreational qualities. The possibilities for developing such areas are considerable: residential development, waterfront park areas, public spaces, a variety of service developments. So far, many successful projects of such transformation have been carried out. This article focuses on an analysis of the conditions and potential of the Port of Zeran in Warsaw and the possibilities for its transformation. The study was carried out by desk research using available spatial data and information provided in scientific publications. A survey was also carried out on a group of 146 Zeran residents. The results of the analyses showed that the local environment is under heavy anthropopressure and the social and technical infrastructure is in very poor condition, while the area also has many advantages and significant development potential. The most important of these include the convenient location, the favourable ownership situation, the multitude of areas not yet developed and the presence of elements related to former activities. The current condition of the harbour offers opportunities for development in both recreational and leisure and residential directions. It is also possible to create a mixed-use neighbourhood, and the potential development would have a positive impact on the entire neighbourhood.