Castro del Monte de Santa Tecla (La Guardia)
The settlers of Monte de Santa Tecla established the hill fort culture, of which there are still important remains. It was discovered in 1913, when a road was opened. Circular buildings predominate, although there are also oval and square ones, the latter under Roman influence. It was declared a Historic Artistic Monument in 1931.
Catedral de Tui
The construction of the cathedral began in 1120, but it was not consecrated until 1225 under the reign of Alfonso IX. It looks like a fortress because of its crenellated towers. Its structure is clearly Romanesque and later diverse decorative Gothic elements were added. From the Romanesque period there are the capitals that top the interior columns, and from the Gothic period there is the portico of the main entrance.
Ruinas del Convento de Santo Domingo
The convent, founded in 1281, belonged to the Dominican order. It is built in Gothic style. Of the church, only the sanctuary with five polygonal chapels is preserved. The body of the church was built in the 17th century and destroyed in the 19th century, as was the convent that housed the cloister and living areas. Part of the Neoclassical work, built to the designs of Álvarez Reguera, is preserved.
Monasterio de San Juan (Poio)
Founded by San Fructuoso in the 7th century, during the Middle Ages it accumulated feudal power over this part of the Pontevedra Ría. The Benedictine monks abandoned the monastery in 1835, because of the Sale of Church Lands Act, and in 1890 the Order of La Merced established itself. The cloister is from the 16th century, the work of the architect Ruíz de Pamames and Master Mateo López. The church is Renaissance style, with Baroque elements in the choir balustrades.
Monasterio de Santa María de Armenteira
This monastery, belonging to the Cistercian order, was founded by the knight Ero de Armenteira in 1168. It has a square cloister, a kitchen and a tower, which are Baroque, from the 17th century. The monastery was abandoned in the sale of church lands of 1835. The monastery church has a Latin cross plan with three naves and three semicircular apses. The central nave is roofed with pointed barrel arches, the lateral naves with cross vaults. At the centre there is a pendentive dome in the Mudejar style. The most notable feature of the 12th century façade is the rose window. Everything has recently been rebuilt thanks to the Association of Friends of Armenteira Monastery.
Monasterio de Santa María de Oia
Building on the Cistercian monastery began along the coast of the Baixo Miño, next to the fishing port of Oia in 1185, with the last of the building work taking place in the eighteenth century on the monastery's church. In 1230 this architectural work of art represented the ideal form of Cistercian Order edifices because of its ornamental simplicity. The only part of this monumental site that can be visited is the church, as the monastery is currently privately owned. The base of the building is Latin cross-shaped with three naves and a sanctuary with five staggered rectangular based small apses, an example of the French influence on the church's design. The transept is covered by barrel vaults, as is the case with the front chapels. The most striking element in the church's interior is its T-shaped pillars held down by stone steps.