via Journal of Archaeological Science, 22 January 2019: New rock art discovered in Sumatra, black drawings which are highly reminiscent of the rock art of the Lenggong Valley.

Until recently, the number and distribution of cave art sites in the western Indonesian Archipelago has been somewhat limited, hindering our knowledge of the character and development of cave art in the area. However, the recent discovery of seven new cave art sites in the karstic area of Bukit Bulan (Sumatra) provides an opportunity to augment current knowledge. Descriptive analyses performed on 84 cave art images from Bukit Bulan demonstrates their similarities with those found in the eastern part of Indonesia, including the similar depictions of humanlike (anthropomorphic) figures drawn in black. Our discoveries in Bukit Bulan not only corroborate the extensive distribution of cave art in the wider Indonesian Archipelago, but it also aligns Sumatra as the westernmost region of Indonesia into the discourse of prehistoric cave art in Indonesian prehistory.

Source: Newly discovered cave art sites from Bukit Bulan, Sumatra: Aligning prehistoric symbolic behavior in Indonesian prehistory – ScienceDirect