Con Son means Con mountain; Regarding to Hun name, according to a legend Con mountain once was covered by dense forest. People went to mountain in order to cut firewood and burned it to have coal. Therefore, in the whole forest there was always smoke like people fumigated. So they called this mountain Hun fumigation.
There is another legend of Hun name: In 10th century, Dinh Bo Linh who had been born in Hoa Lu (Ninh Binh) raised troops to quell revolts of 12 war-lords. Being chased by Dinh Bo Linh's insurgenttroops, the troods leaded by Pham Phong At in the north-east area lurkhad to flee and in Con Son forest. A solution was given by Dinh Bac to catch enemies by burning the forest. Insurgent troops lay in ambush for catching them. The plan was undertaken. Day after day, Pham Phong At's troops could not stand hiding themselves and had to go out to be captured alive by insurgent troops. With fumigating plan, the Con Son mountain has been called Hun mountain and Con Son pagoda has the name Hun Pagoda./.