Knee-deep in the dead

In 1487 for the re-consecration of Great Pyramid of Tenochtitlan the Aztec guys sacrificed thousands of people. According to the historical sources the victims were walking slowly in 4 queues (each several kilometers long) toward the temple and there the priests killed them and cut their heart out continuously for days:

"At the inauguration of this Great Temple in 1487, Ahuizotl ordered the sacrifice of many prisoners of war; an average of 1,000 victims a day were sacrificed over a period of twenty days. Each day blood ran like a river onto the pavement of the Great Plaza, and the stairs of the great pyramid were literally bathed in blood."

http://en.wikipedia.org/wiki/Great_Pyramid_of_Tenochtitlan

We denounce the bloody conquest of Mexico these days, but the Aztecs themselves weren't exactly angels back then.