Anyone walking down Calle Mayor from Plaza Mayor passes by without stopping: between shop windows and residential blocks from the nineteen seventies, a seventeenth-century stone doorway opens up, almost in line with the façade. It is all that remains of one of the city's oldest convent complexes. It is not a small church wedged between buildings, but the only standing fragment of a convent that occupied half a city block.

The Augustinians established themselves here early on, close to the conquest, with an initial location outside the walls next to the Acequia Mayor, where the Asylum now stands; destroyed in the fourteenth century during the War of the Two Peters, the community moved to the royal inn within the walls, with royal protection granted in 1402 by Martín I. Other documentary sources place the founding in 1298, in charge of Father Francisco Salelles, and the move to the old Royal Palace in 1375. Nothing remains of the medieval building: the current temple is baroque, with work completed in 1651 and ornamental additions from the eighteenth century. The municipal catalogue of protections attributes the authorship to Juan Ibáñez, an attribution that the autonomous record formulates cautiously, as the most probable according to the evidence.

It has a single nave, with four chapels opening on each side between buttresses, a semi-circular dome at the crossing and a high choir at the foot; Corinthian pilasters mark the sections of the nave, covered with a barrel vault with lunettes. The dome turns over a small drum, supported on pendentives and crowned by a tall lantern, and the presbytery, square and with a straight head, is covered with an octagonal vault on two scalloped squinches. What is seen from the street is the doorway, and deserves a moment's attention: built in ashlar, with fluted dressed stone jambs and a lintel of radial blocks, framed by two Tuscan columns and a broken pediment with scrolls and pinnacles above an entablature with triglyphs, which leads to the main motif, the order's coat of arms; above, a window framed with genuinely baroque rocailles with the image of Saint Augustine. The lower part of the tower, also in ashlar, resolves the corner of the building.

The high altar altarpiece was dated to 1771, with the intervention of José Vergara and gilding by Gonzalo Coll, and the interior was decorated with frescoes by Joaquín Oliet. In 1835 the convent closes; in 1849 the complex passes to the Town Council, which assigns it to the Civil Government, Treasury Delegation and even military barracks, and only on 19 October 1957 is it returned to the Order of the Augustinians, which allowed the community's return. In 1974, due to urban speculation, everything was demolished except the convent church, which was able to be restored and reopened for worship; in its place residential blocks were erected and the sculptures by Ignacio Vergara that presided over the main niche of the high altar disappeared, in a manner never clarified. It continues to belong to the Diocese of Segorbe-Castellón and remains open for worship, so seeing the dome and presbytery depends on mass times; the doorway, however, can be viewed at any time, and it is best in the morning, when the light enters sideways from the street.