Conical hat making is the unique craft that has been maintained and developed among the Nung An ethnic group in Cao Bang province from generation to generation. Their conical hats are completely different from other regions in Vietnam in terms of the pattern, the material and even the way of making. Hats are handcrafted from bamboo slats and bamboo/banana leaves. The bamboo trees chosen to make the hats must be large and be grown locally, with an average diameter of 5- 8cm and a straight stem. The most important step in making a hat is splitting the slats, completely depending on the skills of the worker. Skilled workers reveal they never use a knife to split the slats. After being split, the bamboo slats are woven into the frame that has two layers - outer and inner. The outer frame layer is woven very carefully and meticulously by the craftsman, as it determines the aesthetics of the finished product. Bamboo leaves, after being picked up, are tied into small bundles and placed in the kitchen to dry naturally until the leaves turn brown and have a certain toughness. Large, long bamboo leaves are used as the middle layer of the hat. Thanks to this middle layer of the bamboo leaves, the hat better protects the wearer from rain and sun. After putting in the bamboo leaves, the worker will press this middle layer tightly and then fix the second layer of frame to make the hat thicker and stronger. The hats will then be dried in the kitchen to help prevent termites, have long durability, and resist sunbeams and rain drops. As all stages of making the hats are done by hand, on average a local can only make four hats a day. Nearly 100 locals are trying to preserve the craft though they know the value of a hat is not high in the market. Though many young people do not learn about conical hat making from their predecessors, artisans earnestly want to preserve the traditional craft as part of their life.