Land, Sea and Human Effort was the central theme of the 28th IGU Congress in The Hague, The Netherlands. This volume contains the key-note addresses highlighting this central theme. Three major issues regarding low-land coasts came to the fore: land-use, environmental quality and safeguarding of the land. An interesting question is whether the concentration of human activities in large urban nodes will continue, or that such nodes and hierarchies will no longer structure our world, because of the ever-increasing importance of all means of communication and transport, as indicated by Johnston. Functions may disperse to specialised environments. A similar specialisation may be encountered in e.g. the development of tourism in the coastal zone. As Gormsen has elucidated, tourism has over time extended in a sequence of spatial 'peripheries'. Consequently, phases in development may be identified with a growing impact and participation of local tourism interwoven with international growth. The environmental quality of coastal zones is seriously under threat, due to ever-increasing population pressure and human exploitation. The major problems are pollution andthe availability of good quality water. Oudshoorn explored the world's resources of drinking water, indicating the great need for political awareness of this huge problem. Cross-sectoral planning is advocated by Oudshoorn, even if water management often trespasses international boundaries and the harmonisation of the planning strategies is mostly difficult. The environmental quality of the coastal zone is alsoaffected by the exploitation of oil and gas resources. Odell demonstrates that the conditions for this exploitation in the North Sea are unique, especially because of the great impact of an international agreement on offshore exploitation. Planning in sea areas is becoming an issue of increasing importance as it has to cope with the many, often conflicting interests, such as shipping, fishery, mining, waste disp [ABSTRACT FROM AUTHOR]