Not far from the foothills of the western slope of Serra de Montejunto, between Vilar and Martim Joanes, the history of Quinta do Gradil has been inextricably linked to the cultivation of vines and wine since 1760. Considered one of the oldest, if not the oldest () estates in the county of Cadaval, for centuries Quinta do Gradil has had a strong winemaking tradition. The property consists of a grand chapel boasting an artistically decorated tower, a residential wing, two wineries, a restaurant, a wine shop and an agricultural area measuring 200 hectares, notably including 120 vineyards planted with local and international varieties from which white, red and sparkling wines are produces, along with a spirit.
Quinta do Gradil was acquired in the late 1990s by the grandson of António Gomes Vieira, precursor of the wine tradition in the family since 1945. In 2000, Luís Vieira started the process of converting the entire vineyard area, placing a strong emphasis on higher quality varieties. The main winery underwent dramatic improvements and the recovered stables were converted into a restaurant. The palace and the chapel, which were in a very advanced state of disrepair when the Quinta was acquired, were cleaned and are now undergoing ambitious upgrades.
The oldest documented references found to the Quinta do Gradil date back to a Royal document from the late fifteenth century. On 14 February 1492, the date of the document, D. Martinho de Noronha received from King D. João II a letter of donation of the jurisdiction and rents from the County of Cadaval and Quinta do Gradil. On the occasion of King D. Manuel I’s ascension to the Portuguese throne, and his actions in favour of members of the House of Bragança, reference was made to Quinta do Gradil in confirmation of the donation granted by King D. Manuel I to D. Álvaro of Bragança, younger brother of the 3rd Duke of Bragança, D. Fernando II, who, having been accused of treason, was ordered to be beheaded by King D. João II, in 1483.
The Quinta was acquired by the Marquis of Pombal during the movement which, from 1760, led to the occupation of municipal lands. Vines were already grown there at the time, a factor that became decisive for the statesman who founded the Companhia das Vinhas do Alto Douro. It remained in the family until the mid-twentieth century, when it was bought by Sampaio de Oliveira.