Tanguar Haor, a Ramsar-protected wetland in Sunamganj, transforms into a vast inland sea during monsoon and reveals lush green paddy fields in winter. It’s a haven for migratory birds — over 200 species visit between November and February. Houseboat stays are the highlight here; floating on calm waters under a star-filled sky, surrounded by silence, is an experience unmatched anywhere else in Bangladesh. Nearby attractions include Watergero (submerged road), Shimul Bagan, and Jadukata River. Best accessed via Sunamganj town, a short drive from Sylhet.