Studying cyber-attacks through cybersecurity exercises, testing and training is difficult to perform on operational critical infrastructure as this could disrupt the critical systems and harm the environment, lives and economy. Therefore, cybersecurity testbeds or ranges with capabilities for simulation, emulation and/or using real components are widely used to understand cyber-attacks and their impact on systems. This paper presents the Cybersecurity Centre being developed at the Institute for Energy Technology in Norway. The Centre aims to provide facilities for providing cybersecurity assessment and training services to stakeholders involved in developing and operating critical Industrial Control Systems (ICS) and Operational Technologies (OT). The Centre, among others, has: a highly configurable platform with real, simulated and emulated components of real-world critical infrastructure; tools for vulnerability assessment, RAMS (reliability, availability, maintainability, safety) assessment, attack injection, incident monitoring, detection and response; high-fidelity simulation technologies for cybersecurity and RAMS events prediction; support evaluation of human preparedness and decision-making during cybersecurity incident process and for operational safety. In this paper, we present the status of the development of the Centre and insights into an experiment being conducted.