The project “Interconnected Smart Cities for Greece 2.0” aims to create a universal Internet of Things (IoT) platform that retrieves and visualizes data generated by existing Smart City systems, achieving semantic interoperability between data and services. The main activities of this project are to establish external compliance with existing platforms and provision of new products and services, to provide first-level integration through data extraction from multiple heterogeneous and vertical implementations, to advance the research community and stimulation of entrepreneurship, and to develop new IoT applications and innovative solutions aimed at Smart City interoperability across the country of Greece.