Chronos, developed by Cosmote, harnesses immersive technologies to reshape user and cultural heritage engagement. Combining augmented reality (AR), virtual reality (VR), and extended reality (XR), the application enables exploration of iconic Greek landmarks such as the Parthenon and Erechtheion. It offers a modern approach to heritage interpretation through interactive storytelling and accurate historical reconstructions. The app operates in two modes, catering to on-site and remote users. On-site, AR overlays digital reconstructions onto physical monuments, recreating their ancient appearance. Remotely, XR technology delivers 3D models, ensuring global accessibility. A digital assistant, Clio, guides users through narrated tours, aiming to promote active exploration and engagement with curated historical narratives. Educationally, Chronos aligns with experiential and multisensory learning principles. It integrates spatial interactivity and narrative immersion, fostering emotional engagement and deeper historical understanding. Its visual, auditory, and spatial elements cater to students, educators, and cultural enthusiasts, shifting users from passive observation to active participation. The app employs AR, VR, XR, and 5G technologies for seamless, high-speed interactions, setting a standard in digital heritage innovation. Despite its strengths, challenges such as accessibility, historical accuracy, and data privacy must be addressed. Ensuring inclusivity and compliance with ethical standards will enhance its impact. Future developments, including multilingual support and expanded content, promise broader appeal and sustained relevance. By reimagining how history is experienced, Chronos highlights both the promise and the constraints of immersive approaches to cultural heritage.