Thẩm Khuyên Cave

The Tham Khuyen is a palaeontological formation located in Vietnam. It dates to the Jurassic period. The cave is located in Lang Son province, about 125 kilometers northeast of Hanoi.

Thẩm Khuyên Cave

The Tham Khuyen is a palaeontological formation located in Vietnam. It dates to the Jurassic period. The cave is located in Lang Son province, about 125 kilometers northeast of Hanoi.