The monumental heritage of Sanremo is composed mostly of religious buildings, which show the course of the different historical ages. The concathedral of San Siro, of very ancient origin, was subject to many transformations, especially in the 17th-18th century. At the beginning of our century, some restorations have brought it back to the medieval forms, whilst the facade is a reconstruction in style of 1903; the central rosette and part of the lateral mullioned windows are authentic. Inside we can see a wooden Crucifix and the altarpiece illustrating St. Siro and Saints by Pancalino.

On the side of the church there is the Canonry which dates back to the 12th century. Both the Oratory of the lmmacolata Concezione (16th century), with frescoes by Giovanni Battista Merano, and the Baptistry of San Giovanni, rebuilt between 16th and 17th century upon the remains of a Romanesque church and of Roman structures brought to light through archaeological excavations, face the square of San Siro. Inside there is a painting by Orazio de Ferrari illustrating the Communion of Maddalena. Near the seventeenth-century Nota Palace, old seat of the town hall, there is the church of Santo Stefano, reconstructed by the Jesuits beginning from the middle of the 17th century. It keeps the painting illustrating the Madonna with the infant Jesus and the Saints Anne and Francesco Saverio by Domenico Piola and frescoes by Giovanni Battista Merano.

Another interesting Baroque work is the church of Santa Maria degli Angeli (1752), with nave and two aisles and a facade rich in stuccoes. It keeps furthermore a picture illustrating St. Clare and St. Siro by a Ligurian-Lombard painter who was active between 1495 and 1500. The town is dominated by the sanctuary of the Madonna della Costa, built with a single nave in the 17th century and enlarged in the presbytery and in the transept in 1778 by Domenico Belmonte. Here we can admire frescoes by Giacomo Antonio Boni, the painting of the Madonna with the infant Jesus belonging to the school of Barnaba da Modena (end of the 14th century) and a painting by Domenico Fiasella.

The ancient castle of San Romolo was situated just below the little Cottolengo of Don Orione, convent of the discalced Carmelites (1645). Along via Matteotti, the Borea d'Olmo Palace stands out among the civil architectures. It is an imposing building, remade in part in the 18th century, whose rooms include the Archaeological Civic Museum where we can find prehistorical finds and material of the Roman Age, and the seat of the cultural Association Famija Sanremasca. In the chapel and in the galery there are frescoes by Giovanni Battista Merano.

Along corso Cavallotti, in the eastern area of the town, we can see interesting villas which date back to the late 19th century, such as villa Ormond, with a luxuriant park, and Alfred Nobel, once residence of the scientist and now seat of cultural manifestations; it contains also the reconstructed Nobel's laboratory and the material concerning his activity.