Động Sơn Mộc Hương

Hang Dơi - Bat Cave - Son Moc Huong Cave

Useful Information

Location: Moc Chau.
Hanoi Highway 6 to Son La town, in the center of Moc Chau town, on the right.
(20.850061, 104.639015)
Open: no restrictions.
Fee: free.
Classification: SpeleologyKarst cave
Light: LightIncandescent Electric Light System
Dimension: L=80m, W=25 m, H=20 m, Ar=6,915 m²,
Guided tours: self guided
Photography: allowed
Accessibility: no
Address: Son Moc Huong Cave.
As far as we know this information was accurate when it was published (see years in brackets), but may have changed since then.
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SEP-1992 archaeological excavation by the Son La Provincial Museum and the Vietnam Archaeological Institute.
24-JAN-1998 declared a national scenic monument.


The cave Động Sơn Mộc Hương (Son Moc Huong Cave) is actually known under the name Hang Dơi (Bat Cave) or in Thai Tham Kia. In the past, there were large flocks of bats living in the cave, now they have migrated to other places. The name is still popular as it was used over decades by guidebooks. The cave is also called Hang Sa Lai (Water Cave) or Hang Nước (Nuoc Cave). The cave contains a large cave river which has water all year round and was used as a source of drinking water.

In ancient times, there was a sacred dragon which flew to the East Sea. When flying over this land, seeing majestic mountains, rich land, cool climate, peaceful sky, the dragon wanted to live here. So he landed and stayed here for a long time. When the dragon finally died, he thanked the land which nourished him and released seven pearls to repay the land. Those pearls became seven hills in the valley, and the dragon's mouth which showed to the south became the entrance portal of the Bat Cave. The mountain range surrounding the valley is the dragon's body. This is the reason why it has so mysterious colors: white in the morning, blue at noon, pink in the afternoon, and purple at sunset.

In 1992 an excavation by the Son La Provincial Museum and the Vietnam Archaeological Institute revealed shards, blades, axes, stone balls, and shards of pottery. They were dated to 3000 to 3500 BP.

To reach the cave you have to walk up a long staircase with 240 steps. The cave is a huge chamber which is 80 m long, 25 m wide and 20 m wide.