The Hoan Kiem Lake is surrounding the Ngoc Son Temple, a small pagoda sitting in the centre of a tiny island.

The temple is from the 13th century and still in full function.

The lake Hoan Kiem has a history of its own. Legend claims in the mid-15th century Heaven sent Emperor Ly Thai To a magical sword, which he used to drive the Chinese from Vietnam. After the war a giant golden turtle grabbed the sword and disappeared into the depths of this lake to restore the sword to its divine owners, inspiring the name Ho Hoan Kiem (Lake of the Restored Sword).