High Quality Content by WIKIPEDIA articles! Aluna is a feature-length documentary film sequel to the acclaimed BBC documentary The Heart of The World: Elder Brother`s Warning (1990). The first documentary showed an ancient Kogi tribe civilisation (the Elder Brother) who emerge to offer their concern for people of the modern world ( Younger Brother). Younger Brother is urged to change or suffer environmental disaster. After offering the warning the Kogi retreat back to civilisation hidden in a mountain in Sierra Nevada de Santa Marta, Colombia.