Over 140 youngsters were buried alongside three adults and 200 animals from the 15th century ritual in Peru.
Scientists released images of the excavation - which began in 2011 - of dead girls and boys aged five to 14 seemingly huddled together in burial pits.
It's said the animals seen with them were probably alpacas or llamas.
The children were killed in the ritual by having their chests cut open, many with their hearts removed.
Early research suggests the children were wrapped in cotton, some with their faces painted red and still with cloth around their heads when the graves were found.
They were buried facing the sea, around 350m away, while the animals were positioned facing the mountains.
Evidence suggests the sacrifice was to do with a ''climatic event'' from the past.