Trinh Nu Grotto or Virgin Grotto is situated on the island range of Bo Hon in the system comprising Sung Sot Grotto, Dong Tien Lake and Luon Grotto. It is 15km south of Bai Chay Beach. For fishermen, Virgin Grotto is their house, but for young lovers, it is considered as the symbol of truly love, and is the romantic place for taking oath of love.
Entering Trinh Nu Grotto, one finds in the middle of the grotto a stone statue of a lying-girl with her long hair hanging down who is looking to the sea in a vain hope. Situated opposite to Trinh Nu Grotto, Trong (or Male) Grotto has a stone statue of a boy who turns his face to Trinh Nu Grotto. One still hears his vain scream in tune with the wind blowing into the cliff somewhere.