For 10 points, what region home to the Iban people, the southwestern neighbor of Sabah, forms the other part of Malaysian Borneo?
Erosion of the Melinau Limestone has formed the karst of this region's Mount Mulu National Park, where the 1981 Lyon expedition found a record-setting chamber in Good Luck Cave. One ethnic group of this region celebrates the deity Singalang the Bird in their festival Gawai Burong, and in 1941, Kiyotake Kawaguchi led an invasion of this region which captured the oil-rich land around Miri. A commission to extirpate this region's pirates between the Samarahan River and Tanjung Datu led to the arrival of James Brooke, who began a dynasty of "white rajahs," founded its capital at ► Kuching, and secured its independence from nearby Brunei. For 10 points, what region home to the Iban people, the southwestern neighbor of Sabah, forms the other part of Malaysian Borneo?
Erosion of the Melinau Limestone has formed the karst of this region's Mount Mulu National Park, where the 1981 Lyon expedition found a record-setting chamber in Good Luck Cave.
Sarawak [or Bumi Kenyalang; accept Borneo or Malaysia before "region"]