European Union's energy strategy for the period up to 2020 builds on eight priority corridors for electricity, gas, and oil. Accordingly, on October 2013, 248 energy infrastructure projects were selected and assessed from a European perspective as the most critical to implement. Particularly, for a project to be included in the list, it has to bear significant benefits for at least two member states, contribute to market integration and further competition, enhance security of supply, and reduce CO2 emissions. Furthermore, by the characterization of "projects of common interest" (PCI), they are indented to benefit from more rapid and efficient permit granting procedures and improved regulatory treatment (European Union, 2014a). The aims of this working paper are, firstly, to introduce and briefly discuss the priority corridors and thematic areas that must be implemented in the coming decade to assist the EU meet its short-and long-term energy and climate objectives; secondly, to outline the key projects of common interest specifically in the South East European, Turkey, and eastern Mediterranean regions; finally, to present the major investment and financial challenges associated with the undertaking and implementation of these projects.