The Church of Mercy is located in the historic center of Penafiel, in front of the Municipal Chamber, and the entire church complex occupies one block. It is a 17th century temple with a single nave, with a large main chapel covered by a cradle vault with coffered ceiling. Its construction constitutes an important milestone in the History of the Santa Casa and Penafiel. The royal approval of 1614, with the attribution of privileges and the increase in legacies, made the institution a local potentate in economic, social and religious terms, they built a worthy Temple of larger dimensions that was adapted to the growth of the brotherhood.
The Brother of Santa Casa and provider in 1627/1628, Abad Amaro Moreira, decided with his Mercy to build the temple in Rocio de Chãs (where the church is), which would pay for the main chapel, where he was buried with his heirs.
The construction of the church took 10 years (1621 – 1631), its size and brotherhood to which it was linked made this temple one of the most important in the city and the region, giving a new centrality to the Vila de Arrifana de Sousa, given that the area surrounding the Main Church was the greatest importance of the town.
Over the years the Church suffered several alterations, both on the front façade and on the side, which explains the countless niches, oratories and chapels that the church presents on the outside.
On the nascent side, the old office house, the sacristan museum (current museum of sacred art) and also the store of our land where the social center was already located.
To the west, facing the Municipal Plaza, a rich unfinished front, in roccaille style, with curved lines and unfinished ornaments, with niches to occupy, in stone, where the frontal composition formed by the door, niche and oculus stands out, flanked by the cornerstones where niches open. The works were started in 1764, but after several conflicts between Mercy and the local Powers, which Mercy won, the works were eventually stopped, having been completed in 1769.
The works were paid for with donations to Nuestra Señora da Lapa.
The solution found was the construction of a chapel in honor of Our Lady based on the design of Señora da Lapa. Currently it is the Chapel of S. Cristóvão.
In 1770 Penafiel was elevated to a city and became a Diocese, with the Church of Mercy chosen as a cathedral on the invocation of St. Joseph and St. Mary, Bishop Frei Inácio of S. Caetano having been the confessor of the Queen. Dª Maria I, never visited her Cathedral.
In 1778 Penafiel ceased to be a Diocese and the church lost its status as a Cathedral.
Inside the Church, the Pipe Organ and the Baroque Chair from the Bustelo Monastery stand out, along with 5 neoclassical altars with white and gold carvings.