Territorial cohesion is a formal EU policy goal since 2010, when it was placed in the Lisbon Treaty, alongside the long-term EU goals of economic and social cohesion. Understandably, by itself, a policy goal is irrelevant if it cannot be assessed. In this light, this article discusses potential methodological approaches to measure territorial cohesion trends in a given territory, their advantages and limitations, based on existing literature. It uses European NUTS 2 and the Portuguese and Polish NUTS 3 as concrete case studies to assess territorial cohesion trends from 2005 to 2020 via a Territorial Cohesion Index. As such, it presents an updated and unique picture on the territorial cohesion trends in Europe and in two specific EU member states, based on available data. It concludes that measuring territorial cohesion trends is challenging mainly due to lack of available data in certain key dimensions of territorial cohesion, but it is possible and needed.

Spatial planning faces challenges in addressing interactions between land and sea. This paper elaborates on land–sea interfaces, which can integrate certain socio-cultural values and related tensions into maritime spatial planning (MSP). In this article, three regional case studies from Estonia, Latvia, and Poland analysed important intersections between the formations of cultural values and spatial dynamics within MSP processes. These cases make it possible to address current challenges, contested boundaries, and spatial planning possibilities to embrace the vibrant and complex ways the sea becomes connected to societal change. The study indicates the multiplicity of land–sea interfaces, which should be involved in MSP through situated places of terraqueous interactions, means of public participation, and meaningful boundaries within mobilised co-existence. The actual and possible tensions in allocating new functions of maritime spaces indicate the importance of coastal landscapes and communities. Thus, MSP practice can employ the land–sea interfaces to advance regional planning through participatory engagements, which reveal sociocultural linkages between society and environment on coastal areas.