The building is located in the Villanova district and overlooks Via San Giovanni, while one side runs along Vico IV San Giovanni and the back is located in Via Piccioni.
According to the Scano, the church was erected at an unspecified time before the middle of the 13th century, while the first attestation of Via S. Giovanni, which probably took its name from it, dates back to 1415. Before 1415, therefore, the church already existed, although explicitly mentioned only in 1550; it was probably rebuilt or, at least, restored in the second half of the 17th century, or between the end of the 17th century and the first 18th century, since in 1697 the Archconfraternity of the Most Holy Virgin of Solitude, which is still based there, was established. In the second decade of the nineteenth century, the building's finances were in a disastrous state and the church was close to closing, as attested by some archival papers relating to the Brotherhood's activities. In 1944, the building underwent restoration, due to the damage caused by the bombing of 1943.
The building, with a rectangular plan, is single-aisle with deep side chapels and an elevated presbytery reduced in width compared to the classroom and from the back of which you can access the small sacristy. The hall and the presbytery are barrel vaulted and set on a projecting frame, and the chapels, in number of three on each side, have the same roof. The choir is leaning against the counterfaçade and overlooks the compass of the entrance portal. The façade was built in the twentieth century, in fact Spano attests to its absence in its description of the building in 1861. It has angular pilasters that originate a theory of ascending arches parallel to the slopes of the gable terminal; it is also divided by a frame frame in a slight object, which delimits an upper mirror with two single-light windows and a rose window, a lower one with an arched portal framed by an arch in the center on small pebbles concluded by capitals decorated with stylized phytomorphic motifs; on the little feet there are two slender half-columns that, after small capitals similar to the previous ones, continue upwards The whole path of the arch; the lunette above the lintel, on which the coat of arms of the Brotherhood hangs, is painted with the image of the Baptist. Hidden from the twentieth-century façade and arranged perpendicular to it is a sailing bell tower, relative to the original construction.
The Archconfraternity of the Virgin of Solitude was established in 1608 by Paul V at the destroyed church of San Bardilio belonging to the Trinitarian Fathers and in 1639 it was joined to the Roman Archconfraternity of SS. Trinity. His mission consisted of the redemption of Christian slaves, to which was later added the office of burying the corpses of those sentenced to hanging. The Spanish government commissioned her to carry in procession on Holy Thursday a crucifix, of natural dimensions, from the church of San Bardilio to the distant Cathedral, where it was stored until the evening of Good Friday, when Christ was brought back to San Bardilio; the tiring journey remained unchanged until 1697, the year in which the Archconfraternity was granted a transfer to the church of S. Giovanni. In 1878, women were also admitted to the religious association, who, together with their confreres, wear a white robe equipped with a hood and a canvas plate bearing the sign of the Trinitarians, consisting of a red and blue cross. Lo Spano informs that on Thursday and Friday of Holy Week, the confreres also carried the simulacrum of the Virgin of Solitude in procession. Still fully active, the Brotherhood continues to carry the great Crucifix in procession up to the Duomo, kept in the third chapel on the left of the entrance; the rite currently takes place on Friday, instead of Holy Thursday, and Christ is brought back to Saint John on Holy Saturday.

Bibliography
G. Spano, Guide to the city and surroundings of Cagliari, Cagliari, Timon, 1861;
F. Corona, Guide to Cagliari and its surroundings, Bergamo, Italian Institute of Graphic Arts, 1894;
D. Scano, Forma Kalaris. Historical street map of the city and suburbs of Cagliari from the 13th to the 19th century, Cagliari, G. Ledda, 1923;
J. Arce, Spain in Sardinia. Cultural contributions and testimonies of his influence, Cagliari, T.E.A., 1982;
F. Masala - M. Pintus, “The Archconfraternity of Solitude. The relief of the church of S. Giovanni in Cagliari”, in 17th and 18th century Art and Culture in Sardinia. Proceedings of the National Congress, Naples, Italian Scientific Editions, 1984;
M. Pintus, “Architectures” in F. Masala - D. Mureddu - M. Pintus, Cagliari Historical districts. Villanova, Cinisello Balsamo, Silvana, 1991.