Virtual Reality (VR) is a robust tool for sponsoring Cultural Heritage sites. It enables immersive experiences in which the user can enjoy the cultural assets virtually, behaving as he/she would do in the real world. Covid-19 pandemic has shed light on the importance of using VR in cultural heritage, showing advantages for the users that can visit the site safely through specific devices. In this work, we present the processes that lead to the creation of an immersive app that makes explorable a famous cultural asset in Sicily, the church of SS. Crocifisso al Calvario. The application creation process will be described in each of its parts, beginning from the digital acquisition of the cultural asset to the development of the user interface. The application is provided for three different VR devices: smartphones equipped with cardboards, headsets, and CAVE. The paper is supported by the 3dLab-Sicilia project, whose main objective is to sponsor the creation, development, and validation of a sustainable infrastructure that interconnects three main Sicilian centres specialized in augmented and virtual reality.