[2] The occupation of the territory of Mesão Frio dates back to the Romans, who occupied a castro in the area around Cidadelhe (from excavations encountered in this location).

[3] The early nucleus of the modern Mesão Frio was founded near the Church of São Nicolau, which was erected on the instruction of Queen Maud of Savoy, Afonso Henriques' wife.

[3][4] Mesão Frio was an early shelter on the Roman roadway; it was initially a respect, successively serving travellers, stabling horses and providing fresh animals, the settlement itself evolving approximately in the 3rd century, from the Latin “mansionis frigidae”.

[4] At one time, there was a legend that the toponymy was attributed to Esteves Gracia Monzon Friwn, who in 942 (during the reign of Ramiro II of León) entered along the Douro River with French knights whom took lands and rechristened them.

[4] At one time, this place was the residence for masons who constructed the bridge erected in Barqueiros (by Queen Maud whose husband had left 3000 Maravedi in his testament for the same).

[8] The regions relief is primarily motivated by the Serra do Marão which is subdivided by the Douro River valley, forming linear hilltops where many of the principal settlements exist.

[9] The localities here are between 400 and 700 metres in altitude (such as Vila Marim and Brunhais), and although the winters continue to be cold, they are less sevre, and the summers are shorter and warmer (with temperatures between 12.5 °C and 14 °C).

[10] Although the primary level of government is the municipal authority, the local administration is operated by civil parish boards (Portuguese: juntas de freguesias).