Visitors from far always regard Lang Son as home to some 
grotesque grottoes, of which Nhi Thanh is one of the most beautiful 
grottoes...
Lang Son has for long had national repute as a year round 
entertainment centre. Attractions such as Dong Dang Town, Ky Lua Market,
 Vong Phu Mountain, Tam Thanh Grotto, Nhi Thanh Grotto are said to be 
very attractive to visitors who are seeking scenic beauty.
Situated
 in Nhi Thanh Street, approximately 1km from the Lang Son City, Nhi 
Thanh Grotto houses the Pagoda of Triple Regions (Buddhism, Taoism, 
Confucianism).
 
   Nhi Thanh grotto entrance
The
 grotto was closely related to the celebrity Ngo Thi Si when he was the 
chief of province between 1777 and 1780. He gave, in a short span of 
time, a new look to Lang Son in term of politics, economy and national 
defense. Especially in the domain of culture, he had the merit to 
discover 8 beautiful landscapes of Lang country including Nhi Thanh 
Grotto. He hired workers to start the renovation of this grotto in 1779.
 The right side area, being on a relatively more elevated land and the 
configuration of terrain better, was chosen to be the place for the 
building of the Pagoda of Triple Regions (in honour of Confucianism, 
Taoism, Buddhism).
 
     Inside the grotto
Being
 a natural cave, Nhi Thanh Grotto lies beneath the Pagoda of Triple 
Regions, with the depth of 600 meters. On the cliffs at the entrance are
 20 inscriptions that are precious historical and literary documents, 
including autographs of famous scholars. The statue of scholar Ngo Thi 
Sy on the cliff engraved in 1779 is a precious work of art. The length 
of a corridor from front entrance to back entrance is over 500 metres 
with many beautiful and picturesque landscapes. Inscriptions can be seen
 today on grotto, which were engraved by famous personalities and poets 
over different epochs.
 
Water-lily in Nhi Thanh grotto
Moreover,
 the grotto has numerous stalactites and stalagmites in different 
shapes, making the grotto look more grotesque and mystical. The entrance
 to the grotto is almost obscured from sunlight, because it is covered 
with a dense foliage of trees. High on the wall to the right side of the
 entrance, there remains a poem carved deep into the stone. The poem was
 written by Ngo Thi Si (1726- 1780) when he was stationed in Lang Son as
 the commander of the Lang Son military post. Ngo Thi Si praised the 
beauty of the magnificent mountain and landscapes possessed by Lang Son,
 
Vietnam.
 Ngo Thi Si was the person who discovered Nhi Thanh Grotto. The name Nhi
 Thanh was chosen by Ngo Thi Si to commemorate his birth place in Ta 
Thanh Oai village in Thanh Oai district, Hanoi. To commemorate his great
 contributions to the grotto, Ngo Thi Si had his portrait carved on an 
interior wall.
"Flows of clean pure white stream water run over 
hundreds of pieces of marble as if it is talking. Turn one's back to the
 stream and look up to a high mountain peak in the from can see the Vong
 Phu peak". Ngo Thi Si’s verses make you feel like to visit Lang Son’s 
beauty spots, and Nhi Thanh Grotto is one of the eight sites that 
attract a large number of visitors to Lang Son...
   Source : VN beauty