Berbak

Berbak belongs to the vast alluvial plain of eastern Sumatra, which forms roughly a quarter of the island. The land is predominantly flat and cut by meandering rivers that drain north-east toward the coast. Those channels carry acidic, peat-stained water and open into beach ridges, intertidal mudflats and a muddy shore where a narrow band of mangrove forest marks the edge of the land.

The surrounding wetland is exceptional. Berbak preserves part of the largest undisturbed swamp forest in Southeast Asia and a peat swamp with the greatest number of palm species. It contains about 600 square kilometres of freshwater swamp forest and roughly 1,100 square kilometres of undisturbed peat swamp, with Shorea rainforest trees and numerous palms.

Tides reach two to two and a half metres at the coast before falling to about one metre upstream, so the rivers are affected by both river flow and sea level. The southern boundary follows the Benu River. For a rural place such as Berbak, this mosaic of forest, acid water and muddy current explains settlement and movement better than a single local monument; people lived within a landscape governed by flooding, tides and boat routes.