High Quality Content by WIKIPEDIA articles! Batak architecture refers to the related architectural traditions and designs of the various Batak peoples of North Sumatra, Indonesia. There are six groups of Batak who speak separate but related languages: the Angkola and the Mandailing to the south, the Toba, and to the north the Pakpak/Dairi, the Simalungun, and the Karo. While the Batak groups are now Muslim or Christian, elements of the ancient Batak religion remain, particularly amongst the Karo.