The term Balsamão comes from a legend about an emir who demanded that each village pay him the tribute of a maiden. When the tribute fell on Castro Vicente, its inhabitants prepared to revolt. During the battle, a lady appeared with a vase of balsam in her hands, healing the wounded and enabling the Christians to win, and they built a chapel to the Lady of Balsamão (balsam in her hand).
In 1754, Friar Casimiro Wysynski settled here and founded the first house of the Marian Order of the Immaculate Conception in Portugal. In 1834, the Congregation became extinct and only returned in 1954.
The shrine is characterized by its Passion chapels, of which the Senhor da Costa Chapel stands out for its miraculous image.
Inside the church, the nave's ceiling with Mariological themes and the chancel's ceiling, painted by Damião Bustamante, with floral and architectural motifs and Our Lady of Balsamão in the center, stand out. The convent also has a museum with liturgical objects and paintings.