## 2 Materials and Methods
### Activity I: Starting Point Prior to the Deepening of the Metaverse
#### 2.2.2 Milestone I.2: Selection of the Case Study  
For the development of the work, the Vaquero's Hermitage, located in the world heritage city of Caceres, Spain, was selected. The property has the following characteristics (Table 2): \begin{table}
\begin{tabular}{c c} \hline \hline \multicolumn{2}{c}{**Characteristics**} \\ \hline Protection & Cultural and architectonical heritage \\ \hline Form & Complex geometries (vaults, arches, domes \\  & [13], etc.) \\ \hline Details & Singular elements \\ \hline Dimensions & Architectural elements that can be walked \\  & through in VR \\ \hline Metaverse & Interiors to create immersive experiences \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Required values for the object of study. The Vaquero's Hermitage is part of the oral and written tradition of the city of Caceres (Figure 6). This hermitage is called the cowboy in reference to the profession of [PERSON], to whom, according to tradition, around 1326, the [PERSON] appeared in the location that the hermitage now occupies. This apparition is the origin of the invocation of [PERSON] and, therefore, of the imposing monastery of [PERSON], and it is one of the most important Marian traditions and surely the most significant for Hispanic people [47,48]. The origin of the construction of the hermitage dates back to the beginning of the 17 th century. Later, to this first work, probably as early as the 18 th century (see Figure 7), a baroque-style dressing room was added, which has a polygonal floor plan and is adorned \begin{table}
\begin{tabular}{c c} \hline \hline \multicolumn{2}{c}{**Characteristics**} \\ \hline Name & Vaquero’s Hermitage \\ \hline Coordinates & 39\({}^{\circ}\)28\({}^{\prime}\)27\({}^{\prime\prime}\) N 6\({}^{\circ}\)22\({}^{\prime}\)06\({}^{\prime\prime}\) W \\ \hline Altitude & 426 m altitude above sea level \\ \hline Construction & Siglo XVII \\ \hline Extension & Siglo XVIII (baroque-style extension) \\ \hline Area & 281.73 m\({}^{2}\) \\ \hline Other features & It borders the Almohad wall of Cáceres [46]. \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Technical characteristics of “Vaquero’s hermitage”. Figure 6: Planimetry of the execution project for the restoration of the Vaquero’s Hermitage of Cáceres. Author [PERSON]. with plasterwork. This is an assumption since we did not find any documentary references to this dressing room or its financing, date of construction or master builder, but in any case, it is evident from the style and conformation that it is an element subsequent to the hermitage chapel. The hermitage complex was completed with a sacristy, located on the side of the main wave, from where one can access the hermit's house, which is a simple and modest house, typical of a complex of this type, where an old kitchen and a typical cupboard stand out. From this house, there is access to a patio located on the extrados of the wall, from where the old canvas and the outside of the dressing room can be seen. This space is a unique and ancient element that deserves to be studied in detail since it houses several remains of constructions that could have archaeological and historical value. Thus, it contains a drain made with large pieces of slate that could have been used before the hermitage and could have been used to evacuate the water from the wall; on part of it, there are some pieces of slate of uncertain function (covers, walkways, etc. ), and with these, we can see the remains of several constructions that could well have been part of the wall. 2.3 Milestone I.3: Generation of Digital Twins from Photogrammetry with Unmanned Aerial Vehicles (UAVs)  
First, photogrammetry is carried out using a Structure from Motion (SfM) methodology [49], in which the reality capture process is carried out through the use of drones, and the subsequent processing of the data captured is performed in Agisoft Metashape.