The Tinku is an ancient harvest ritual in the remote highlands of the Bolivian Altiplano dating from pre-Inca times. It merges both catholic and traditional beliefs and iconography in a heady mixture of sacrifice, offerings, blood and devotion to bring good fortune, health and happiness.

The rites are specific to a remote area between Oruro and Potosi where the indigenous population still eke out an existence from subsistence farming at an altitude of over 4000 metres. Many aspects are a product of the zealous proselytizing of the Spanish conquistadores in the area who manipulated similarities in iconography in their efforts to convert the indigenous population.

Festivities begin in remote villages and over the course of three days gradually move down to the regional centre of Macha gathering devotees on the way in music, dance and finally violence. Prayer and blessings to God are combined with blood and offerings to the Pacha Mama or Mother Earth.

On the first night, small communities gather to make offerings of coca leaves and alcohol to both Pacha Mama, the Inca god of nature, and Christ on a cross that is kept in a small shrine and acts like a totem, protecting and looking after the village. Llamas are sacrificed with the spilt blood a further offering to Pacha Mama in the hope for a good harvest and prosperity. Their hearts are eaten first. Conversations become more intense over copious bowls of homemade alcoholic chica.

The villagers, led by the cross, then move together gradually down the valley from the mountains dancing, drinking and socializing. First disparate communities from all corners gather at the parish church. They dance three times around the church playing traditional music before taking the sacred object for blessing by the local catholic priest. Following formalities, festivities continue as the entire parish gradually arrive and socialise providing an opportunity for old friends to catch up and young people to look for a partner.

On the third day, the outlying parishes finally descend on Macha, the regional centre. They announce their arrival with repetitive tunes played on pan pipes creating an almost hypnotic effect for the dancers. Once again the communities dance around the main plaza, stopping to circle around the cross before taking them to be blessed in the church.

When some communities cross paths and old rivalries are renewed, challengers fight each other with their fists. They hit with straight arms and do not defend themselves as the blood that falls is regarded as an offering to Pacha Mama. Bravery and success in combat also boosts status with many young men looking to stake their claim for a wife. While combats are supposed to be one-on-one, police often have to intervene when they spill out of control and become a general brawl letting off tear gas in order to break up the crowds. Due to deaths in previous years, the Bolivian government is proposing to prevent the festival from taking place in its current form.