What is "baralku"

In Yolngu culture, Baralku (or Bralgu) is the island of the dead and the place where the Djanggawul originated. It is said to lie to the east of Arnhem Land, and is where the Barnumbirr creator-spirit (who is identified as Venus) came from (see Aboriginal Astronomy) as she guided the Djanggawul sisters. Barnumbirr is also said to live on the island and rises into the sky as Venus.