Nguom Boc, locally known as Dry Cave, is located on the west slope of the Lam Son mountain range, at Ban Nua hamlet, Lam Son village, Hong Viet commune.
Nguom Boc is famous for witnessing many historical events of the revolutionary life of President Ho Chi Minh during the period 1942-1945. From end of March to August 1942 he moved from Pac Bo to the military base at Lam Son and organized secret meetings in Nguom Boc, being lovingly called “Ong Ke” (or Father in the Nung language) by the local people. In May 1945 at Nguom Boc, President Ho Chi Minh met with leaders of Cao Bang-Bac Kan-Lang Son Inter provincial Party Committee to prepare for the historical August 1945 uprising.
Nguom Boc was also the weapon factory where Mr. Le To and his co-workers lived and worked during the French war. It was also here, in October 1950, that President Ho Chi Minh chaired the Review Conference of the Border Campaign and talked with workers of the weapon factory and representatives of the people of Hong Viet commune, Hoa An district.
Many relics found here also show that Nguom Boc was home of the early Neolithic people, i.e. the early Hoa Binh Culture, c.10,000 years ago. In the famous legend Pu Luong-Slao Cai of the Tay people, Nguom Boc is the first residence in Cao Bang of these legendary characters.
Geologically, Nguom Boc cave is developed in limestone, which was formed under shallow and warm marine conditions c.360-270 million years ago (Carboniferous-Permian periods). Its entrance still records evidence of ancient flows and terraces, indicating recent (so-called neotectonic) uplift movements.
Nguom Boc cave was recognized as National Historical Monument under Decision No. 02/2004/QĐ/BVHTT dated 19th January2004.