The Atlantic Forest South-East Reserves — the Reservas de Mata Atlântica do Sudeste — are a group of protected areas in the Brazilian states of São Paulo and Paraná, inscribed by UNESCO as a World Heritage Site in 1999. Together they safeguard one of the largest and most biologically rich surviving stretches of the Mata Atlântica, the coastal rainforest that once ran the length of Brazil's eastern seaboard and has since been reduced to a small fraction of its original cover.
Most of the protected forest clings to the Serra do Mar, the 1,500-kilometre system of mountain ranges and escarpments that runs parallel to the Atlantic coast of southeastern Brazil, dividing the narrow sea-level littoral from the inland plateau. It was on these steep, cloud-wrapped slopes — hard to clear and hard to reach — that the richest remnants of the Atlantic Forest survived while the lowlands around them were cleared for cities, ports and farms. From the air the contrast is stark: dense, unbroken forest on the escarpment, giving way abruptly to cleared land and urban sprawl below.