Cat Tien National Park Crocodile Lake, nestled deep into the UNESCO-recognised world biosphere reserve, is only accessible by a 10km pick-up truck ride and then a 5km hike. The Crocodile Lake or Bau Sau in Vietnamese is situated in Cat Tien National Park, Dong Nai Province. We had spent a remarkable morning trekking through 15km of rainy jungle within the park.