The tale goes that Le Loi King came across a shining metal bar when he visited his friend. It turned out that his friend caught the bar in one of his attempts for fish. The King asked for the bar, brought it home and moulded it into a sword. All of a sudden, there was two words printed on the sword “Thuan Thien” (harmonious with heaven).
Le Loi then understood that the sword was a gift from heaven. He used it for the battle against the war with a neighbouring country. At the beginning of 1428, when peace prevailed, on one of his trip to the Thuy Quan (now Hoan Kiem) Lake, there was a tortoise rising above water and shouting: “Please return the sword to the Dragon King”. Without hesitation, the King threw the sword to the lake. The tortoise took the sword and dove down the water. From then on, Thuy Quan became Hoan Kiem lake.
About the lake
The lake is not only special in her history. The water color of Hoan Kiem Lake is not commonly found in other lakes elsewhere in the country: greenish, with dark or light shade depending on the reflection of the sky. The lake is full of tortoise, which is second to none to be found among Vietnamese lakes. If you are lucky, you will catch sight of these giant animals rising out of water. And because tortoise is considered a sacred animal in Vietnam’s culture (along with dragon, phoenix and unicorn), Hoan Kiem Lake then become a holy place that nurtures tortoise.
Before and even after Hanoi’s massive expansion in 2009, Hoan Kiem lake is still a pride of all Hanoians and the center for any distance measurement. Nowadays, it’s still a gathering place yet new Hanoians may live too far to count their distance to the lake. Still, as you walk by, you will be able to witness the pace of life in this peculiar city.
If you can wake up early in the morning, at about 5 a.m., you will see lines and lines of oldies and teenagers doing anything from yoga to tai-chi to aerobics (read Our Blog on early morning exercises in Hanoi). It looks as if the whole city was up and running for morning exercise. They work out in group or by themselves, with or without equipment. In the course of one of the high profiled meetings in Hanoi, an Australian prime minister also joined the early jogging around the lake.
In the afternoon to the South end you can see a matrix of motorbikes twisting along the lake. Blending in is a gang of “cyclo” – the famous three-wheeled carriers that take tourists with cameras handy around. To the North end where the old quarters lies, an influx of colourfulclothes and shoes will dazzle you, together with the smell of trees and coffees.
When darkness takes over, you can see couples holding hands walking side by side along the lake, trying to breathe in the breeze of summer night or keep warmth against the winter cold. If you have time and really want to observe Hanoi’s life, sit down on one of the stone bench, enjoy the view and have a good talk with some local friends over an ice-cream cone.
Turtle Tower (Tháp Rùa) on Hoàn Kiếm Lake, the natural habitat of the turtle in central Hanoi
Through work by Farkas et al., most authorities classify leloii as a junior synonym of the Yangtze giant softshell turtle. However, some Vietnamese biologists, such as Hà Đình Đức, who first described leloii, and Le Tran Binh insist that the two turtles are not the same species. Le points out genetic differences as well as differences in morphology. However, Farkas et al. repeated their 2003 conclusion in 2011, stating that differences between specimens may be due to age and that the genetic sequences used were never sent to GenBank. They also criticized the fact that Le et al. violated ICZN Code by renaming the species from leloii tovietnamensis on the grounds of “appropriateness”. Another genetic test was done in 2011 when the turtle was rescued and cleaned, which allegedly showed it to be female and distinct from the R. swinhoei of China and Đồng Mô, Vietnam. However, the results were not formally announced, and some are skeptical of these results, given the difficulty of sexing turtles and the lack of the claimed genetic proof.
Đức has also hypothesized that Emperor Thái Tổ of the Lê Dynasty brought the turtles from Thanh Hóa Province and released them in Hoàn Kiếm Lake. Recently, Đức and some researchers found skeletons of giant turtles in Yên Bái, Phú Thọ and Hòa Bình provinces.
Depiction of the turtle Kim Qui with the Restored Sword, in the temple of Hoàn Kiếm
Stories of the Hoàn Kiếm turtle began in the fifteenth century with Lê Lợi, who became an emperor of Vietnam and founder of the Lê Dynasty. According to legend, Lê Lợi had a magic sword given to him by Kim Qui, the Golden Turtle God. One day, not long after the Chinese had accepted Vietnam’s independence, Lê Lợi was out boating on a lake inHanoi. Suddenly a large turtle surfaced, took the sword from Lê Lợi, and dove back into the depths. Efforts were made to find both the sword and the turtle, but without success. Lê Lợi then acknowledged the sword had gone back to the Golden Turtle God and renamed the lake Hoàn Kiếm Lake (or Hồ Gươm), “The Lake of the Returned Sword”.
A preserved turtle on display in the Temple of the Jade Mountain
Near the northern shore of Hoàn Kiếm Lake lies Jade Island, on which the Temple of the Jade Mountain is located. On June 2, 1967, a Hoàn Kiếm turtle died from injuries caused by an abusive fisherman that was ordered to net the turtle and carry it, but instead hit the turtle with a crowbar. The turtle’s body was preserved and placed on display in the temple. That particular specimen weighed 200 kg (440 lbs) and measured 1.9 metres long (6 ft 3 in). Until that time, no one was sure if the species still lived.
On March 24, 1998, an amateur cameraman caught the creature on video, conclusively proving the elusive creatures still survived in the lake. Prior to its recent rediscovery, the turtles were thought to be only a legend and were classified as cryptozoological.
In 2000, professor Hà Đình Đức gave the Hoàn Kiếm turtle the scientific name Rafetus leloii.
Presently, if R. leloii is considered to be identical to R. swinhoei, there are four living individuals. Three turtles are in captivity, two of them in Chinese zoos and another in Đồng Mô (which appears to be a R. swinhoei), while the fourth being the controversial specimen in Hoàn Kiếm Lake.
By the Spring of 2011, concerned with the Hoàn Kiếm specimen’s more frequent than usual surfacing, and apparent lesions on its body, the city authorities started attempts to capture the giant reptile of Hoàn Kiếm Lake, and take it for medical treatment. On February 9, a local turtle farm operator, KAT Group, was chosen to prepare a suitable net to capture the sacred animal. The first attempt, on March 8, 2011, failed, as the turtle made a hole in the net with which the workers tried to capture it, and escaped. An expert commented, “It’s hard to catch a large, very large soft-shell turtle.” On March 31, in an unusual act, the turtle went to the shore to bask in the sun.Finally, on April 3, 2011, the giant turtle was netted in an operation that involved members of the Vietnamese military. The captured creature was put into an enclosure constructed on an island in the middle of the lake, for study and treatment. According to the scientists involved, the turtle was determined to be female, and genetic research suggested it was distinct from the R. swinhoei turtles in China, and Đồng Mô in Vietnam. 
Some witnesses believe there are at least two or three turtles living in Hoàn Kiếm Lake and that the “smaller” one appears more regularly. Đức is critical of these suggestions.
Despite eyewitness sightings of two or more turtles, Professor Đức believes that there is only one specimen left in Hoàn Kiếm Lake. Peter Pritchard, a renowned turtle biologist, believes that there are no more than five specimens left.
The lake itself is both small and shallow, measuring 200 metres wide, 600 metres long, and only two meters deep. It is also badly polluted, although the turtles could conceivably live underwater indefinitely, coming to the surface only for an occasional gulp of air or a bit of sun. According to Pritchard, the turtles are threatened by municipal “improvements” around the lake. The banks have been almost entirely cemented over, leaving only a few yards of rocky beach where a turtle might find a place to bury her clutches of 100 or more eggs.
Plans are underway to clean the lake of pollution, and the construction of an artificial beach has been proposed to facilitate breeding. Dredging the lake, to clean up its bottom, was carried out in February and March 2011.