Hoan Kiem Lake, or the Lake of the Restored Sword, is located directly in the centre of Hanoi. The name is derived from a legend involving Emperor Le Thai To, in which he came across a giant tortoise while cruising on the lake. The tortoise took his sword that had secured victory against the Chinese aggressors of the Minh Dynasty. The emperor named the lake after this episode.
Every morning, the surrounding park fills with locals who arrive to exercise and play badminton. By the way, there still are a few tortoises who call this area home.
Hoan Kiem was already considered the most beautiful lake in Hanoi when Ngoc Son Temple was built on a small island during the 19th century. Saint Van Xuong, considered one of the brightest stars of Vietnam's literature and intellectual circles, was worshipped here. National hero Tran Hung Dao was also worshipped after he lad the Vietnamese people to victory over both Mongolian and Chinese invaders.
The temple as it is seen today is the result of renovations made by Nguyen Van Sieu in 1864.
A great Hanoian writer, sieu had a large pen-shaped tower built at the entrance of the temple. On the upper section of the tower are three Chinese characters: ta thanh thien, which means that to write on the blue sky is to imply the height of a genuine and righteous person's determination and will.
Also at the entrance are: a dai nghien, or ink stand, carved from stone and resembling a peach, which is placed on the back of three frogs on top of the gate to the temple; and The Huc, or the place where the first rays of morning sunshine touch.
On the way to the temple are several cau doi, parallel sentence boards, placed on the wall. cau doi were part of traditional word puzzles played by Hanoi's intellectual class.