Which Swampland Covers ~1,398,800 Hectares? The Sundarbans

The Sundarbans — the world's largest contiguous mangrove forest — spans approximately 10,000 km² (1,000,000 hectares) across India and Bangladesh. The figure 1,398,800 likely refers to hectares of the Bangladeshi portion alone (6,017 km² = 601,700 ha) plus Indian portion (4,263 km² = 426,300 ha) = ~1,028,000 ha total. Some sources cite the entire UNESCO Biosphere Reserve (including buffer zones) at ~1.4M ha.

Key Facts

• Location: Ganges-Brahmaputra-Meghna delta, Bay of Bengal.
• Countries: Bangladesh (60%), India (West Bengal, 40%).
• UNESCO: World Heritage Site (1987/1997), Biosphere Reserve (2001).
• Ecology: Mangroves (Heritiera fomes — sundari), Bengal tiger (~100 in BD, ~100 in IN), Irrawaddy dolphin, saltwater crocodile, 260+ bird species.
• Human: 4.5M in buffer zone; honey, fish, wood, nypa palm collection.
• Threats: Sea-level rise, salinity, cyclones (Sidr 2007, Amphan 2020), poaching, upstream dams (Farakka).

If the question expects a specific named swamp at exactly 1,398,800 units — the Sundarbans is the only mangrove system of that magnitude. The unit is almost certainly hectares (not acres or km²).