The SEMSON: South Eastern Mediterranean Spatial Planning Observatory Network project originates in the successfully evolving INTERREG-IIIB/CADSES project ESTIA-SPOSE (CADSES area) and aims at the promotion of spatial development policy integration in SE Mediterranean area. The Archi-Med macro-region, consisting of 4 EU members and several third peripheral countries, is currently a scattered area due to the administrative and political constrains, although the historical roots and common features between the Mediterranean basin countries (cultural corridors, tourism exchanges, navigation, common traditions, common interest for environmental protection, hazards, etc.) might address a hopeful perspective for a common spatial integration through territorial cooperation actions, a fact that requires a territorial overview of the socio-economic, urban network, accessibility and environmental identity of the area. The main objective and concrete results of SEMSON project is to enhance the ability of the SE Mediterranean countries to collaborate on spatial development and planning issues at a trans-national level through particular activities and actions related to the foundation of core territorial indicators, the testing through Pilot Applications, properly addressed to illustrate the specialized features and outstanding advantages as well as the bottlenecks of the macro-region and finally the establishment of a spatial observatory platform, as well as networks composed of administrative authorities and academic institutes responsible on spatial and regional planning. The overall geo-graphical area for the implementation of the project will cover the total territory of the Archi-Med macro-region and the focus area for the pilot application of the Territorial Indicators System will cover the EU members territory. The added value and the synergy to all other similar projects (e.g. ESPON and ESTIA-SPOSE) is the target to reveal the neglected common spatial portrait of the Southeast Mediterranean Basin which is totally discerned from the rest European macro-regions. The already produced ESPON indicators are not sufficient and they do not give a specific analysis of the spatial trends of the Archi-Med space, especially due to their general content and nature. For this reason, the avoidance of duplication is secured, due to the applied methodology which will reveal and promote the specialized features of SE Mediterranean area and will contribute to the lack of comparable knowledge for this space (general spatial structure, coastal and insular character – spatial interactions, cultural corridors, hazards situation identification, territorial identification of Turkey, etc.). The major expected impact of the project is the better territorial understanding of the SE Mediterranean space through comparable and reliable data and territorial indicators which will enhance the spatial cohesion of the entire SEMSON area and the deliverables will include comprehensive reports and special documents, conferences and workshops, pilot applications, institutional structures, database and web site. The target group of SEMSON is consisting by all public and private agencies and institutions that are directly and/or indirectly involved with spatial planning and spatial development policies. A rough approximation might lead to about 150 agencies which are expected to become involved as potential users. The direct and indirect beneficiaries (around 500-700) are the practitioners from the public and private sector, research institutions involved with spatial planning and spatial development policies as well as the specialized departments in the various administrative tiers, as well as the relevant institutions and practitioners from the neighboring countries within Archi-Med space (Egypt, Syria, Lebanon, Turkey, Israel, Palestinian Authority and Jordan). Finally, among the beneficiaries the women participation at least with a percentage of 30% will be a target of the project, aiming at the promotion of the gender equality.