Tam Thanh Grotto is one of the famous grottoes in Lang Son, lying west of Ky Lua Street. Its door is approximately 8m high, opening to a corridor with 30 stone steps carved into the mountain. There are dense groves hiding the grotto from the sun. Poet Ngo Thi Si (1726�1780) carved one of his texts on the grotto wall while he was a Mandarin guard in Lang Son.

The poem praises the magnificent natural beauty of the area, more specifically the sound of the water stream falling on hundreds of rocks, almost like a graceful murmur. Vong Phu Mountain, meaning "waiting for a husband," is located nearby. Here, one can explore a grotto with marvelous stalactites and a statue of Buddha.

Mau Son Mountain

Chi Lang Defile

Ky Cung Temple

Tam Thanh Cave

To Thi Mountain

Nhi Thanh Cave