It is located in the Plaza of the García Naveira Brothers. Its construction began in the mid-16th century, on the site of an earlier chapel, when the Dominicans arrived in Betanzos. Work continued throughout the 17th and 18th centuries. It is a masonry building, except for the main chapel, which is partly built in ashlar stone. Both the nave and the presbytery are covered with vaults. Three chapels flank the nave. On the façade is the entrance door, featuring a modest Renaissance portico, above which there is a niche with Saint Dominic and a large window. Particularly noteworthy is the tower built in the 18th century. From this tower, the traditional San Roque balloon is launched on the night of 16 August. Convent of Santo Domingo. The Dominicans settled in the city following a testamentary bequest by the priest Antonio González de Sosa and a donation from a noble family. They established chairs in various subjects within the complex, which came to house up to 16 friars. The cloister with its windows, the arches of the conventual rooms and the staircase leading to the cells are especially noteworthy. After the confiscation of church property in 1835, the building passed into municipal ownership and the Dominicans were expelled from the town. Today it houses the Municipal Library and the Museo das Mariñas.