The Grotto of the apparitions is the heart of the Sanctuary. The spring and the statue of Our Lady of Lourdes within it are the centre of attention of all the pilgrims. The Grotto, by itself, says much about the Message of Lourdes. A hollow in the rock, it echoes the words of the Bible: “The Lord is my rock, my salvation, my citadel” (Psalm 62:7). The rock is black and the sun never penetrates the Grotto, in contrast with the Apparition (the Virgin Mary, the Immaculate Conception), who is only light and smiling radiantly. The niche where the statue is placed marks the place where the Virgin Mary most often stood: it is like a window that opens onto the kingdom of God from this obscure world.

The Grotto is a place of prayer, hope, peace, respect, unity and silence. When passing through the Grotto or standing in front of it, each person has his or her own personal understanding of what it means.

Popes John Paul II and Benedict XVI both came to pray at this Grotto.