St. Mary Roman Catholic Church, formally the Church of the Immaculate Conception of the Blessed Virgin Mary, is in the third oldest Roman Catholic parish in Detroit, Michigan. Designed by German-born Peter Dederichs and built for the formerly ethnic German parish of the 19th century, it is located at 646 Monroe Street in what is now considered the heart of the Greektown Historic District in downtown Detroit. It is often called "Old St. Mary's Church" to avoid confusion with other St. Mary's parishes: in the Redford neighborhood of Detroit, or in nearby Royal Oak, Monroe, or Wayne. The former church was built in 1841. The school, built in 1868, was the first of the new buildings of the current complex. The rectory (1876); new church (1884–1885), and convent, completed in 1922, comprised the remainder. The convent was demolished in the early 2000s and replaced with a community center designed to resemble the 1841 church building. St. Mary Parish has been staffed by the Spiritans or Holy Ghost Fathers since 1893. It was previously administered by the Franciscan Fathers (1872–1893) and the Redemptorist Fathers (1847–1872). History The parish was founded in 1834 by Father Martin Kundig to serve the German-speaking Catholic immigrants who settled in this part of the city. The first church was constructed in 1841 at this site on land sold to Bishop Peter Paul LeFevere for one dollar by Antoine and Monica Beaubien, two of the area's early ethnic French settlers. The materials for the church cost an additional $239. The Beaubiens also donated four bells for the new church. The cornerstone for the current structure was laid in 1884 and it was completed in 1885. Its German born and trained architect, Peter Dederichs, was a parishioner of the Church; he also designed nearby Sacred Heart Church. In the early twentieth century, Father Joseph Wuest, Pastor of Old St. Mary's, had three grottos constructed at the rear of the church. One is the Baptistry on the Epistle side of the building. It depicts the scene described in the Canonical Gospels of the Baptism of Jesus. Next to the Baptistry is a replica of the Shrine of Lourdes. Within this grotto is an altar where weekly mass is celebrated. Older members of the church say that Father Wuest collected the rocks he used in the construction during a trip to Lourdes, France. On the opposite side of the church