The Church of Mercy in Aveiro is located in the same square, and city hall. Initially, the design of the Church answered the Italian architect Filippo Terzi. Construction under his leadership began in 1585. It is worth noting that this architect also built many other buildings in Portugal, which included not only the Church but also the FORTS. The Church was built a very long time. The construction was completed in 1653 another architect, the Portuguese Manuel Azenha.

The temple is famous for its Grand portal and the facade, decorated with tiles-Azulejos of the nineteenth century. The facade of the temple is decorated with producing a strong enough impression classic portal, made of limestone. Later in the decoration of the portal elements were added in the Baroque style. The entrance to the Church is decorated with four Corinthian columns. In the lower part between the columns made niches, in which are stone sculptures. In the upper part, between the columns earlier in the niches were statues, but then instead of them made Windows. In addition, the facade is decorated with a stone statue of our lady of Mercy. In the upper part of the façade is the Royal shield and armillary sphere (an ancient astronomical instrument).

Inside the Church has a long, high nave and very chic. The walls are covered with tiles-Azulejos with patterned ornaments of the sixteenth century. In the altar part of the temple attracts the attention of the vaulted ceiling. It is worth noting that the ceiling is made of stone, brought from the province of Ansan, and is used in the construction of monuments in this part of Portugal.