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, the Mandailing to the south, the Toba, to the north the Pakpak/Dairi, the Simalungun, and the Karo. While the groups are now Muslim or Christian, elements of the ancient Batak religion remain, particularly amongst the Karo. The bale ("meeting hall"), rumah ("house"), and sopo ("rice barn") are the three main building types common to the different Batak groups. The rumah has traditionally been a large house in which a group of families live communally. During the day, the interior is shared living space, and at night, cloth or matting drapes provide families with privacy. Most Batak now live in modern homes, and many traditional houses are abandoned or in a poor state of repair. The architecture and village layouts of the six Batak groups also show significant differences. Toba Batak houses, for example, are boat-shaped with intricately carved gables and upsweeping roof ridges. Karo Batak houses rise up in tiers. Both are built on piles and are derived from an ancient Dong-Son model. Villages The Toba and Karo Batak live in permanent villages and cultivate irrigated rice and vegetables. On the other hand, the Angkola, the Mandailing, and the Pakpak practiced slash-and-burn agriculture which required frequent changes of location and their villages were only semi-permanent. Irrigated rice cultivation can support a large population, and the Toba and the Karo live in densely clustered villages, which are limited to around ten homes to save farming land. Unirrigated slash-and-burn agriculture supported smaller villages with only several houses. All villages are located near watercourses and fields. Internecine Batak warfare before the twentieth century saw villages sited in easily defensible positions. High bamboo stockades fortified Pakpak villages and barriers of earthen ramparts with bamboo fencing and trees. Each Batak group has its own rules and traditions guiding village layout. Toba Batak houses are laid out side by side with their front gables facing the street. Traditionally, each house would have had a rice barn granary opposite which would a complementary row in the village. The street formed between the row of houses and the row of granaries is known as the alaman and is used as an area for work the drying of rice. The Mandailing also build their houses in