More than 1,000 kilometres southwest of Mahé, Aldabra feels less like an island destination than a world set apart. Four main coral-limestone islands enclose a shallow lagoon, with narrow channels connecting it to the Indian Ocean. The Seychelles Islands Foundation describes the atoll as about 35 kilometres long and 15 kilometres wide; UNESCO recognizes a protected World Heritage property of 35,000 hectares. The difference between a visitor’s map and the protected marine landscape matters: the atoll is a connected ecosystem, not a single beach.
Aldabra is a raised coral atoll, built from ancient reef limestone and repeatedly lifted above sea level. Tidal water moves through its channels twice a day, reshaping shorelines, flats and mangrove wetlands. The hard, uneven limestone surface—often called champignon terrain for its mushroom-like forms—supports a mosaic of habitats. Lagoon, reef, seagrass, mangroves and dry scrub meet across a landscape where access is difficult and natural processes remain unusually visible.