In 1875, it was decided, with the approval of Pope Pius IX, to build a new church dedicated to the rosary. The Rosary Basilica was the third of the churches to be completed after the Crypt and the upper basilica. Designed and built by the architect Leopold Hardy, it took six years to complete (between 1883 and 1889). During construction, the rocky hillside had to be excavated and concrete foundations sunk to a depth of three metres below the level of the River gave. The Church was inaugurated in 1889 and consecrated on 6 October 1901 by Mgr Langenieux, Archbishop of Reims. The Virgin Mary appeared to St Bernadette holdling a rosary in her hands. The Rosary Basilica is dedicated to this theme. Its dome bears a crown and a cross, commemorating the ceremony of the coronation of our Lady of Lourdes.
The Rosary Basilica is neo-Byzantine in style with three naves laid out in the shape of a Greek cross. 52 metres long and 48 metres wide, it can hold about 2000 people. Those who enter the basilica are welcomed by the open arms of Our Lady of Lourdes, painted on the vaulted ceiling of the choir by Edgar Maxence in 1920. Pilgrims recite the rosary guided by the mosaics in the fifteen side chapels, each of which illustrates one of the Mysteries of the Rosary. On the left: the five joyous mysteries. In the centre in the apse: the five sorrowful mysteries. On the right: the five glorious mysteries. The mosaics were completed by Gian Domenico Facchina between the years 1895 to 1907.
The mosaics were applied on the paintings of eminent European artists at the end of the 19th century, such as Melchior Doze of the Nimes school (The Annunciation and The Nativity), the Parisian artist M. Grellet (The Visitation and The Finding of Jesus in the Temple, The Crowning with Thorns, The Crucifixion, The Resurrection), Louis Fournier also from Paris (The Presentation, The Scourging), the Aragonese Felipe Maso (The Carrying of the Cross), the Nantais artist Edgar Maxence (The Descent of the Holy Spirit, The Ascension, The Coronation).
The facade is dominated by a majestic portal with a Romanesque arch of finely worked grey sandstone featuring a bas-relief (by the sculptor Maniglier, 1890) of Madonna and child offering a rosary to St. Dominic of Guzman. The windows are by Claude Lavergne.