The so-called Castelo Mourisco provides an accurate model of the elevated function of architecture. It is all the more interesting because it is the headquarters of an internationally-renowned institute of biomedical sciences, and its meticulous design reveals the humanist ideals of Oswaldo Cruz, its founder. Only through a faultless alliance between founder and designer can architectural creations like this one arise; it transcends the limits of construction to symbolize the fusion of science, history and art. Analysis of the various stylistic resources used in the building justifies their selection and continued relevance, since for a century it has not only occupied the heart of the Manguinhos campus, but also continued to express the modern spirit of the institution it harbors.