The Sundarbans, a unique biogeographical region along northern fringe of the Bay of Bengal spreading over parts of the lower Ganga delta extends from the Hugli estuary of West Bengal in India to the Meghna estuary in Bangladesh in a west to east direction. This estuarine deltaic coastal plain houses one of the most diverse and rich mangrove forest ecosystems in the world and is also the habitat of the famous Royal Bengal tiger. In situ and ex situ human interventions, altered hydrological regime, changes in water and sediment flux, reduced spill area of tidal flushing, increasing incidence of cyclones, and global environmental change and consequent sea level rise have variously affected this forest ecosystem. Based on historical literature, available thematic maps, satellite data products, and detailed field investigations, this chapter brings out that recorded large-scale human intervention in this area dated back to 1810 when parts of the mangrove forests, particularly in the Indian segment, were divested of natural vegetation cover to accommodate agriculture, fisheries and human settlements by constructing embankments around the islands, which has altered the natural sedimentation pattern and the tidal flow has been pushed upstream. Field investigation brought out that the bio-tidal accretion continued uninterrupted into the mangrove infested islands, which now stand at relatively higher elevation compared to the reclaimed islands. Sea level rise in this area is estimated at 4.9 mm/year, the highest in the Indian coast. Several intermittent areas between embankments and rising sea levels are under coastal squeeze. Morphological, ecological and physical buffers are under severe stress. Landscape ecology of the region as a whole changed with dominance of socio-ecological processes. Ecosystem degradation of both reclaimed and forested Sundarbans and resulting socio-economic hardship are major problems which are further aggravated due to increased frequency of cyclones. This chapter deals with some of the issues and outlines certain nature-based measures to restore mangrove ecosystem of the Sundarbans.