The church in Gietrzwałd was enlarged and expanded into a pilgrimage church in the years 1878–1884 by the Paderborn cathedral and diocesan architect Arnold Güldenpfennig. The church was opened in 1970 by Pope Paul VI. elevated to the minor basilica. During the apparitions of the Virgin Mary in Dietrichswald, 13-year-old Justyna Szafrynski and 12-year-old Barbara Samulowski reported that they lived in Dietrichswalde (today Gietrzwałd in the Olsztyński powiat in the Polish Warmian-Masurian voivodeship) from June 27 to September 16, 1877 the Virgin Mary appeared several times. In contrast to the Marpinges apparitions of the Virgin Mary, which took place almost at the same time, the Prussian authorities reacted with caution. Bishop Maximilian Kaller recognized Dietrichswalde as a diocesan pilgrimage site. [10] The apparition was only officially recognized by his successor as Bishop of Warmia, Józef Drzazga, in 1977 (on the 100th anniversary) and thus approved the worship. Source: Wikipedia