Urbanization occurs now more rapidly than before, due to the development of compact cities or urban sprawl, threatening quasi-natural areas, especially those protected within/near built-up ones. Europe lacks laws dedicated to natural protected areas within built-up areas, which are subject to the same provisions as natural protected ones, or a legislative vacuum. This research aimed to find the best planning approach for resiliently conserving and developing these areas and establishing grounds for a new tool used for planning the proximity of natural areas within cities. The methodology involved selecting two groups of countries, Nordic and eastern European, and treating these areas differently. The choice was based on specific political history. The study analyzed the legislative and planning framework and compared the approaches of 11 analyzed countries to pinpoint the basic aspects accounted for and applied to other European territories, in order to preserve the characteristics of urban morpho-typology and the particularities of local landscapes. The comparison results suggest solutions such as adopting specific regulations for urban protected areas and their adjacent zones through legal documents, completing/detailing environmental legislation in Nordic countries, adopting laws dedicated to protected natural areas within and/or close to built areas, and changing the approach to protecting natural areas with urban planning or land use tools.