Ngoc Son Temple and Hoan Kiem Lake area is the official conform one heritage since it was recognized as a national monument and now a special national monument. It is among special cultural symbols of the capital.

Tourists on The Huc bridge

With around 1,800m in total length of its circumference, Hoan Kiem lake (also known as Sword lake) is as beautiful as a flower basket in the heart of the city, surrounded by the streets of Dinh Tien Hoang, Le Thai To and Hang Khay. 

The lake surface looks like a large mirror which reflects ancient trees quivering, the luxuriant willows hanging down, temple roofs, ancient pagodas, old tower covered with moss and  new buildings appearing to reach blue sky. 

Tourists discovering the relic of Ngoc Son temple and the surroundings of Hoan Kiem lake

The lake is the remnant of a section of the Nhi Ha (Red) River chocked by sandbanks in the north and east. The lake was once named Luc Thuy (Green Water) because its water remains green all year round (this name appeared in the  Le Restoration dynasty). 

Therefore, Hoan Kiem lake used to be part of  Cai (Red) river, the Mother River in which delta the  civilization of the Vietnamese ancestry was formed. 

The lake has been both a nature museum of water, history as well as mythology and an endless topic for researcher, art lovers in many fields at home and abroad.

Hoan Kiem lake means “Restored Sword” lake or the Sword Lake for short. The name comes from a legend from  the  15th century. 

It has it that  the Chinese Ming invaders  conducted   wickedly cruel policies to exploit the subjected Dai Viet people, for which the people felt a vindictive hatred. At that time in Thanh Hoa province,  there was a fisherman named Than. 

One night, he felt an unexpected weight when hauling in the net. Than thought that he might have pulled in a great catch but it turned out to be an iron bar. Shortly after, Than threw the bar into the water and casted the net in another section of the river. Feeling heavy the second time as pulling the net, and he saw the iron bar again. He again threw it into the river. 

On the third time the iron bar still was caught in the net. Than felt strange, lighted a fire to see the iron bar more clearly and found out it’s a blade. Later, Than joined Le Loi's insurgents. Once the general Le Loi, in a visit to the Than’s barrack,  saw a light flashed from the blade in the dark corner, the general came closer and  seaw  it engraved with two words "Thuan Thien" (Heaven's Will). 

At another time, Le Loi saw treetops had a unlikely light through a forest, he climbed up and found a hilt carved with jade. 

Remembering the blade at Than’s house, he picked up the hilt, and amazingly saw it fitted the blade. Since then, Le Loi took the sword along, together with Lam Son insurgents, he fought throughout the 10 year resistance against the Chinese Ming invaders. 

After successfully expelling the Ming invaders, one day, King Le Loi was boating on the Ta Vong lake (present-day Hoan Kiem lake) when the King of the Sea commanded a golden turtle to ask him to return  the magical sword. 

As the boat was gliding to the middle of the lake, suddenly a great tortoise surfaced. At the King's command, the boat slowed down. Standing on the side of the boat, the King realized the magical sword hung at his waist was moving. 

The golden turtle lifted its head upwards, approached the King's boat and said: "Your Majesty, would you please return the magical sword to the King of the Sea?” 

The King pulled his sword out and threw it towards the golden tortoise. The golden turtle   caught the sword in its mouth and dived under the water and bright lightning flashed up to the sky. 

Since then, Ta Vong lake has been called Sword lake or Hoan Kiem lake. The surroundings of Hoan Kiem lake with its religious center Ngoc Son Temple has become one of the special cultural symbols of the capital.

Hanoitimes