Sleeping Vishnu at the Budhanikantha Temple (Nepal)
Lord Vishnu is depicted as in Yoga Nidra, a state when one appears to be asleep but is fully conscious, lying down on Adisesha, the Snake, floating on the Ksheera Saagara, Ocean of Milk.
The eleven heads of the Snake cradle Vishnu's head. Shesha is the eternal, multi-headed king of the serpent deities known as Nagas, and also is the servant of Vishnu.
For more info about this Temple and this Sleeping Vishnu sculpture, read sacredsites.com/asia/nepal/budhanilkantha.html.