The city of Zaruma in Ecuador, a former Spanish colony, has heavily relied, throughout its history, on the mining exploitation of the region that was the primary reason for the city’s foundation and development but, at present, after this activity became illegal, it poses a significant risk to the city's structure. In this paper, combining different sources of information, we present a study of the constructional system of the historical timber houses of Zaruma built during the last mining boom of the area and characterized by peculiar techniques—such as the “bahareque”—that reflect the cultural and historical evolution of the region. The study, while offering a contribution to the knowledge of the city's architectural heritage, could also provide a valuable basis for a coherent restoration activity able to balance the conflicting needs of structural safety and architectural conservation.