Sumatra is the most culturally diverse island in Indonesia. Across an area the size of France live over forty ethnic groups, each with its own language, architecture, cuisine and system of customs. For travellers this means that every few hundred kilometres you find yourself in a different world — with entirely different food, dress and ways of greeting a neighbour.
Main ethnic groups
Batak people
The Batak inhabit the highlands around Lake Toba in northern Sumatra. They are divided into six groups — Toba, Karo, Simalungun, Pakpak, Angkola and Mandailing — and although they share common roots, they differ in language, customs and architecture.
A common trait is their pronounced hospitality and emphasis on the clan system (marga). Your surname tells more than just who you are — it determines who you may sit with at the table and who you may marry. The Batak are predominantly Christian (Protestant and Catholic), which is unusual on Muslim-majority Sumatra.
Traditional houses with their characteristic saddleback roofs still stand around Lake Toba, on Samosir island and in villages near Berastagi.
Minangkabau
The Minangkabau live in western Sumatra, around the cities of Bukittinggi and Padang. They are known for two things: their matrilineal system and their cuisine. Matrilineal means that property passes through the female line and after marriage the husband moves to the wife’s family — it is one of the largest matrilineal societies in the world.
Their traditional houses (rumah gadang) have roofs shaped like buffalo horns and are among the most photogenic buildings in Southeast Asia.
Although devout Muslims, the Minangkabau maintain a parallel system of customary law (adat) that coexists with Islamic law. This tension between tradition and faith is one of the most fascinating aspects of their culture.
Acehnese
At the northern tip of Sumatra live the Acehnese — the most conservative Muslim community in Indonesia. Aceh is the only province in the country where sharia law applies. In practical terms this means more conservative dress (covered shoulders and knees) and limited access to alcohol.
Despite their conservative reputation, the Acehnese are extraordinarily hospitable. Banda Aceh, the provincial capital, is a modern and pleasant city with historic mosques and memorials related to the 2004 tsunami.
Religion
Several religious traditions coexist on Sumatra. Most of the island is Muslim — Islam arrived in the 13th century through traders from India and Arabia. The Batak in the north are predominantly Christian (missionaries arrived in the 19th century). And beneath both layers persist animist and Hindu traditions — particularly in rituals, healing practices and the relationship with nature.
In practice this looks like hearing Sunday hymns from a church in a village by Lake Toba, the call to prayer from a mosque a few hours further on, and finding talismans at the market that locals say “work for everything”.
Cuisine
Sumatran cuisine is among the most intense in Asia. The foundation is rice, coconut milk and spice pastes (bumbu) prepared fresh.
Rendang — beef slowly braised in coconut milk with a blend of chilli, galangal, lemongrass and other spices. The process takes hours; the result keeps for days. It originates from the Minangkabau and is considered one of the best dishes in the world.
Nasi Padang — a serving style typical of Padang cuisine. Ten to twenty small dishes are placed on the table — chicken, beef, fish, vegetable, sambal, eggs. You take what you want and pay for what you eat.
Soto Medan — a coconut milk soup with chicken, prawns and rice noodles. Yellow, aromatic, filling.
Babi Panggang Karo — grilled pork with a Batak spice blend. Available in the north, in Christian areas. In the rest of Sumatra, pork is not served.
Kopi Luwak — coffee made from civet droppings. Sumatra is one of the few places where it is still produced by traditional methods from wild civets. Commercial farms with caged civets are ethically problematic — ask about the source.
Traditional architecture
Each ethnic group has its own building style, but the common denominator is houses raised on stilts with prominent roofs.
- Rumah Gadang (Minangkabau) — a large clan house with horn-shaped roof peaks, decorated with red and gold carving. The finest examples stand at Istana Pagaruyung near Batusangkar.
- Jabu Batak (Karo Batak) — a massive wooden house for several families, with a tall saddleback roof. The village of Lingga is a living museum.
- Rumah Bolon (Toba Batak) — smaller but richly decorated, with carved symbols on the facade. You will see them on Samosir island.
Etiquette and travel tips
- Remove your shoes when entering a house, mosque or some shops. Watch what locals do.
- Right hand — offer things with your right hand. The left is considered unclean.
- Dress — outside beach areas, cover your shoulders and knees. In Aceh this is required; elsewhere it is a sign of respect.
- Photographs — ask before photographing someone. Most people agree and are happy to pose, but asking is a matter of good manners.
- Food — if someone invites you to eat, declining is impolite. At least taste something.
- Alcohol — in most of Sumatra, alcohol is available in limited supply. In Batak areas around Toba, palm wine (tuak) is drunk. Elsewhere, it is best not to expect it.
What you will take home from Sumatran culture
Sumatra is not a place you visit for architecture or museums. You experience culture directly — in the food a neighbour cooks for you, in a ritual you are invited to, in a conversation over coffee that lasts two hours. This is precisely what separates Sumatra from tourist destinations. And precisely why it makes sense to travel with a guide who can introduce you — not as a tourist, but as a guest.