Leonardo da Vinci - The Virgin of the Rocks, 1508, 190 x 120 cm. Placing the Virgin Mary and the Christ child in a rocky cave was quite unconventional and controversial. The Virgin Mary, the Angel Uriel, Christ, and John the Baptist all form a triangle, each person somehow connected to the next. The Virgin Mary has her left hand extended carefully over the head of Christ, while Uriel is gently propping him up. At the same time, she is delicately pointing to John. The plants within the dark cavern symbolize the fertility and life that Mary represents, while the white flowers symbolize her purity. Leonardo's delicate use of colour and sfumato are beautiful examples of his advanced understanding of distance and depth. The artist’s Milanese clients must have worried about confusing the two infants, for a later hand has given John an identifying scroll and a cross clumsily rooted in one of Leonardo’s exquisite studies of plants.