Built in 1697 by the confraternity of Nossa Senhora do Postigo das Verdades, next to the old chapel with the same invocation, its completion works were led by Canon Domingos Gonçalves Prada. He, living in a house adjacent to the chapel, financed the remainder necessary for the completion of the chapel, and in exchange for his help, he would be allowed to open direct access from his house. 

In Mannerist style (transition between Renaissance and Baroque), it is characterized by its rectangular plan, gable roof, frontispiece delimited by Tuscan pilasters and topped by a triangular pediment. Inside, the altarpiece has a reticulated scheme that intersperses four paintings depicting St. Dominic, St. Joseph, St. John the Baptist and Our Lady of the Rose and in the center is displayed the image of Our Lady of Truths. 

This work is particularly important because it is a unique example of the transition from the Renaissance style to Mannerism in the history of the evolution of the art of carving in Porto. On the other hand, the symbols of a Eucharistic nature – wine leaves, bunches of grapes, phoenixes and naked children – of its decoration reveal the approximation to the Baroque and which has been defined as the National style. 

Originally located in one of the arches of the old city wall, more specifically at the wicket of lies, the sculpture of Our Lady of Truths represents the virgin with the Child in her arms and is probably from the fourteenth century, attributed to the Coimbra workshops.