This chapter introduces current topics in the discussion of human encounters with coasts and coastal areas in what is termed the Mesolithic period (c. 9500–3800 cal bc), with special focus on northern and western Europe, from Ireland in the west to Latvia in the east. It also serves to place the 15 other chapters (Chapters 2–16) of this volume into this ‘field of play’ – not least in a research historical perspective, and introduces the structure of the book. The diversities of the coastal environments and their development in the areas from the Atlantic to the Baltic are, on the one hand, decisive for Mesolithic people’s encounter with the coast and the sea (with regard to e.g. tides, climate, topography and specific faunal and mineral resources). On the other hand, they also have consequences for the preservation of archaeological coastal sites, for example being submerged or not, or yielding organic or non-organic material. These conditions have, in return, an important impact on the respective knowledge of the human use, exploitation and meanings of coastal areas in the Mesolithic period. The chapter focuses on these different ‘landscapes’, including varieties of coast and sea, different coastal zones and their taphonomic biases, social organization, mobility and networks, and coastal sites as people’s remains, their diversities, economic aspects, aspects of site placement, cosmological dimensions, as well as issues of time and chronology. It addresses how the obvious regional differences can broaden our understanding of Mesolithic human–coast relations, by comparing, across regions, different archaeological, environmental and methodological situations and scales and by sharing approaches, and it eventually formulates future research questions and perspectives.