The Metaverse has recently gained popularity, bridging physical and digital realms via Extended Reality (XR) technologies. Such technologies provide unprecedented opportunities for visualizing decentralized Internet of Things (IoT) systems. This paper introduces HoloWoT, a Mixed Reality (MR) application that provides immersive device interaction for IoT devices, leveraging the Web of Things (WoT) and the Asset Administration Shell (AAS) Asset Interface Description (AID) for automated UI generation and direct device-app communication, without the need for any middleware or cloud-solutions. The HoloWoT’s immersive experience has been evaluated by fifteen users with a satisfaction rate of 87%. Through HoloWoT, it is possible to visualize and interact seamlessly with IoT devices on the field to gain valuable insights and can be considered a first step that would pave the way for immersive Digital Twin (DT)-augmented applications.