This image is from a shrine to Mary outside the town of Nepi, which is north of Rome towards Viterbo. Before Christianity came to the area there was a temple to the goddess Diana, but in the year AD 520 some monks destroyed the temple and built a monastery and a basilica on top of its ruins. Two of these monks, St. Anastasio and St. Nonnoso, became known for their sanctity and, after their deaths, they were adopted as protectors of the nearby town after their deaths. The monastery, which was abandoned in 1258, had a grotto above it that was dedicated to Mary under the name Santa Maria “ad Rupes”, meaning St. Mary among the rocks.
The grotto is now more of a chapel than a cave, and the image which can be found there is a fairly recent (16th Century) painting, probably replacing a more ancient fresco. What is notable about this picture is the way that Mary delicately contemplates her sleeping son, and some see in this image a parallel to the pieta. +