This grotto is hollowed out of soft white rock and this rock is considered holy by new mothers. Some women mix soft white chalk with their food, and praying to Our Lady of the Milk for increase in their milk. According to tradition a drop of Mary’s milk fell upon the stone and it turned white.
People send letters and baby pictures from around the world to the Milk Grotto for good luck and blessings. A corridor or tunnel leads to other part of the cave where there is another church.