The Facebook post received more than 24,000 likes and 11,000 shares as of Thursday.
The user said she found a black panther drinking water inside a basin on her way to the Phanoen Thung mountain. Kaeng Krachan National Park is located between Phetchaburi and Prachuap Khiri Khan provinces, covering an area of 2,914 kilometres. It is the largest national park in Thailand.
She admitted that she was shocked by the sight. She said that she locked the car and turned off its engine to ensure the black panther would not get scared.
"Suddenly, it [black panther] got close to my car with its fierce eyes," she said, "After making sure that my car did not pose a threat, the black panther laid down on the ground and rolled around on its back like a cat."
She added that the black panther returned to the forest when another car arrived at the scene.
"When I arrived at the Phanoen Thung mountain, a national park official told me that I was lucky to have seen a black panther because they don’t show up easily," she added.
She also asked people who plan to go to national parks to drive their vehicles slowly, so that wild animals living there are safe.