Nguyen Ngoc Thien

Hidden deep within Cat Tien National Park, Bau Sau is a vast wetland ecosystem that forms the “ecological heart” of the forest. Its size shifts dramatically with the seasons: in the dry months it contracts to just 100 – 150 hectares, but with the rains it expands to more than 2,500 hectares, creating an immense flooded landscape. Reaching Bau Sau requires a 14-kilometer journey from the park entrance: nine kilometers by jeep or bicycle, followed by a five-kilometer trek beneath the ancient canopy, along trails alive with the calls of birds and gibbons echoing through the pristine wilderness.

Crocodylus siamensis, or the Siamese crocodile, is an endemic species in Bau Sau

Bau Sau is far more than an enchanting landscape. In 2005, it was designated Vietnam’s second Ramsar site, joining the list of wetlands of international importance. Its ecosystem of semi-flooded swamps, melaleuca groves, and seasonal wet meadows forms a vast “biological reservoir,” storing and regulating the region’s water supply. It also serves as a sanctuary for hundreds of aquatic species – many rare and endangered – recognized in both Vietnam’s Red Book and the global Red List.

Alongside the Siamese crocodile, Bau Sau is home to gaurs, deer, wild boar, waterbirds, and primates such as long-tailed macaques and yellow-cheeked gibbons. Together, they create a vivid tapestry of biodiversity, affirming Ba Sau’s position as an ecological treasure of the southern forest.

A crocodile’s journey back from the brink

The Siamese crocodile (Crocodylus siamensis) once ranged widely across Southeast Asia. Averaging over two meters in length, with long, slender snouts and sharp teeth, these freshwater reptiles thrived in swamps and lakes, feeding on fish, crabs, birds, and small animals. Villagers in Cat Tien tell stories of the days when these crocodiles were so numerous that shining a torch across the lake at night would reveal hundreds of glowing eyes, scattered like stars on the dark water.

By the late 20th century, relentless hunting for skin and meat, habitat destruction, and genetic dilution in commercial farms had driven the species to the edge of extinction. By the early 1990s, scientists believed that Vietnam’s wild populations of Siamese crocodiles had all but vanished.

Boats bring visitors to the core of Cat Tien National Park

From breeding farms back to wetlands

Faced with this crisis, Cat Tien National Park, together with WWF and international partners, launched a special program to reintroduce purebred Siamese crocodiles into the wild. Beginning in 2001, carefully selected individuals from breeding farms – screened through DNA testing to ensure genetic purity – were released into Bau Sau. The release of the first ten crocodiles marked the start of a long and challenging journey.

Over the years, at least five more releases followed, bringing the total number of reintroduced crocodiles to around sixty. Each animal was closely monitored. They were tagged, observed for hunting and adaptation skills, and tracked in their new wild home. These efforts soon bore fruit: in 2005, rangers discovered a clutch of wild-hatched crocodile young – living proof of a successful recovery.

By 2019, surveys counted at least 286 individuals, 228 of them juveniles. By early 2025, more than 500 were recorded, making Bau Sau home to the largest population of wild Siamese crocodiles in all of Southeast Asia.

A living symbol of Bau Sau

Among these hundreds of crocodiles, one stands out – an old male affectionately known to the rangers as “May Bac” (Silver Eyebrows). His name comes from the two pale streaks above his fierce eyes, as if age had turned his brows silver. May Bac is one of the oldest survivors from the very first batches of purebred crocodiles released into the wild.

The true overlord of the swamp, May Bac is both majestic and fearsome, with massive jaws, yellowed teeth, rough skin draped in algae, and parasites clinging to his body. Wherever he glides, the waters part and the other males retreat, yielding their territory. May Bac recently sired a clutch of healthy young, proof of his enduring vitality.

The park is home to many rare animals

Stories of this crocodile’s boldness have become legendary, as in the chilling true tale of him snatching a ranger’s underwater camera in his powerful jaws.

Where ecotourism meets conservation

Today, Bau Sau is a popular ecotourism destination. Visitors can spend the night at the ranger station, watch wildlife from observation towers, and listen to birds greet the dawn. People come to experience the silence of flooded wetlands and ancient forests still untouched by Wi-Fi or phone signals.

Yet tourism always carries the risk of disrupting fragile ecosystems. For this reason, Cat Tien National Park is carefully managed: visitor numbers are limited, safety regulations are enforced, and access to crocodile breeding zones is strictly prohibited. This delicate balance allows travelers to experience the park sustainably while preserving the integrity of its natural environment. Above all, it reflects a belief that humankind and nature can coexist and share the same land in harmony.