Hoan Kiem Lake was already considered the most beautiful lake in the city when Ngoc Son Temple was built on Ngoc (Jade) Island, in the northern part of the lake during the 19"1 century. It was dedicated to Van Xuong, once considered as the brightest star in Vietnamese literary and intellectual circles, and Tran Hung Dao, the national hero who led the Vietnamese people to victory over Mongol aggressors in the 13''' century.
The temple, as it is seen today, is attributed to the restoration efforts of Nguyen Van Sieu in 1865. Nguyen Van Sieu, a great Hanoian writer, had a large pen-shaped tower (Thap But) built at the entrance of the temple. On the upper part of the tower are three Chinese characters, Ta Thanh Thien, which mean "to write on the blue sky is to imply the height of a genuine and righteous person's strength and will."
The temple is open daily from 8am to 5pm;