Thi Nai Lagoon

Thi Nai Lagoon is the largest brackish-water lagoon in the former Binh Dinh Province, now part of Gia Lai Province, located northeast of Quy Nhon city and separated from the sea by the Phuong Mai Peninsula. Covering about 5,000 hectares and stretching over 10 km, it features mangrove forests, tidal flats, fishing villages and Con Chim islet. It is notable for its ecological diversity, scenic sunsets and views of Thi Nai Bridge, formerly Vietnam's longest cross-sea bridge.

Visitors can expect a broad, shallow brackish lagoon surrounded by mangroves, mudflats, fishing villages and aquaculture rafts. The landscape is open and tranquil, with views of Phuong Mai Peninsula and Thi Nai Bridge. Areas to explore include boat routes through mangrove channels, Con Chim islet for birdwatching, and waterfront villages. Activities are low-key and nature-focused, centered on sightseeing, photography and boat trips, especially at sunrise and sunset.

Thi Nai Lagoon was the site of the historic naval Battle of Thi Nai in 1801 between the Tay Son dynasty and the Nguyen lord Nguyen Anh, a decisive engagement that contributed to the fall of the Tay Son and the establishment of the Nguyen dynasty. The lagoon has long served as a natural harbor and fishing ground for the Quy Nhon region.

The lagoon supports traditional fishing and aquaculture communities whose livelihoods depend on its brackish waters. Fishing villages, stilt houses, and local seafood culture around the lagoon reflect the coastal heritage of Quy Nhon and the former Binh Dinh region.