Augmented Reality (AR) technologies are increasingly utilized as a means of stimulating immersive experiences to cultural site visitors, mainly through visual superimposition of interactive digital elements onto the physical world. Recent research has investigated the use of Audio AR (AAR) in heritage sites, wherein visitors listen to spatially registered sound which could be attributed to ‘talking’ physical artefacts. A parallel trend in the audience engagement programs of cultural institutions involves the employment of AI chatbots which are engaged in dialogues with followers or visitors to provide meaningful responses to a number of user questions. Herein, we present Exhibot, an intelligent audio guide system aiming at enhancing the user experience of cultural site visitors. Exhibot involves the combination of AAR and chatbot technologies to enable natural visitor-exhibit interaction, while also leveraging IoT devices to contextualize the delivered information. The key contribution of the proposed system lies in the interplay of AAR, chatbot and IoT technologies to create immersive learning experiences in the context of an integrated cultural guide system. Exhibot has undergone field trials to validate its usability and utility in realistic operational conditions. As a case study, we have chosen the statue of a prominent politician situated at a central square in Heraklion, Greece. The evaluation results indicated a very positive attitude of users, which is attributed both to the sense of immersion evoked by the AAR-powered storytelling and the natural human-like conversation enabled by the chatbot.