Ho Hoan Kiem means ˉLake of the Restored Swordˇ, a body of water that lies at the heart of Hanoi. Until the 15th century it was called Luc Thuy or ˉGreen Waterˇ. Legend has it that during the Ming occupation (1407-28), General Le Loi was presented with a magical sword by a divine turtle that lived in the waters. With the help of this sword, Le Loi expelled the Chinese from northern Vietnam and established himself as Emperor Le Thai To. Later, when the emperor was sailing on the lake, the turtle rose to the surface and reclaimed the sword. Ever since it has been known as Ho Hoan Kiem. Den Ngoc Son, or ˉJade Mountain Templeˇ is one of the most revered religious complexes in the capital. Established by the scholarly mandarin Nguyen Van Sieu (17991872) appropriate symbols of learning and literature mark the temple complex.