Kalimantan is the Indonesian part of the island of Borneo. It occupies the central and southern regions of the island.
The Kalimantan regional flag can be seen here: 
Kalimantan is divided into four provinces:
There was a war in the region between the indigenous Dayaks, who follow Kaharingan Hinduism, and Madurese immigrants, who were moved here as part of a government transmigration programme that operated, in various forms, from 1905 until 2001. The Dayak fighters are known for their ferocious tactics, such as the beheading and mutilation of their victims.
The Indonesian Confrontation was a border conflict over the disputed island of Borneo, between British-backed Malaysia and Indonesia in 1962-1966.
Kalimantaan is a novel by C. S. Godshalk, which is set in Borneo.