Extended Reality (XR) offers a fascinating capability to transport individuals through time and space. However, are there ways to keep the users grounded in reality while exploring distant landscapes or unfamiliar places? We propose in this paper a Point of Interest portal-based navigation technique that takes full advantage of the available, often limited, physical space of the user while still facilitating natural walking in a virtual environment. This technique can be beneficial for the exploration of Points of Interest (PoIs), which is a recurrent situation in virtual museum visits. It ensures consistency between the physical workspace while a user moves from one PoI to the next, enabling applicability beyond Virtual Reality (VR) and into Mixed Reality (MR) scenarios. The connection of different PoIs in the virtual space is achieved with portals, which are strategically placed in the physical workspace. In order to evaluate the efficiency of this technique, in terms of time, presence and user subjective preference, we conducted an experiment with 19 participants who visited artefacts in various rooms of a fictitious virtual museum. The results indicated that the PoI-based portal technique delivers performance comparable to the most well-known navigation technique (teleportation), while maintaining a balance between immersion in the virtual environment and awareness of the physical space, and offering better spatial consistency. Therefore, it can be considered a viable solution for cross-reality interaction.