TwinCity is a DestinE demonstrator, that provides a city-scale digital twin to support urban analysis and decision-making. It integrates heterogeneous satellite data, lidar data and model output, to provide insights about climate, energy and urban nature, suitable for policymakers.

The co-design process placed end users at the centre of Twincity’ development, ensuring that the resulting solution responds to concrete operational needs. By engaging city stakeholders throughout the design phase, this demonstrator was able to identify the datasets, functionalities, and access mechanisms that provide the greatest value for local decision-makers. This collaborative approach highlighted the importance of high-resolution observations, long-term historical records, and interoperable services that can be integrated into existing workflows.

Beyond informing technical choices, co-design fostered a shared understanding between technology providers and users, helping to bridge the gap between advanced Earth observation capabilities and practical urban applications. The resulting demonstrator delivers tools and datasets that are directly relevant to climate resilience planning, empowering local authorities to monitor environmental changes, assess vulnerabilities, and support informed adaptation strategies.

This instance showcases its usage on the French city of Marseilles.