The plastinated specimen of the giant turtle is now on display at Ngoc Son Temple, which stands on a small islet inside the lake in downtown Hanoi.
The turtle was one of the last of the Yangtze giant soft-shell turtles, species Rafetus swinhoei, of which there are just three known specimens now, two in China and one in a lake outside the city.
The female turtle, which had reached the fullest growth of 2.08 meters (6.82 feet) long and 1.08 meters wide and weighed 169 kilos when she was still alive, was sacred to the capital city and its people.
Referred to as Cu Rua, or Great-Grandmother Turtle, she was the symbol of a legendary turtle, the legend being that a golden turtle God showed up in the lake to take back the sword that King Le Loi, a national hero, had borrowed from a Dragon King in the 15th century to help him fight Chinese invaders. That is where the name of the lake, Hoan Kiem, (Returned Sword and now Sword in short) comes from.
According to local experts, while the oldest tortoise in the world is now about 186 years old, the turtle in the Sword Lake is estimated to have lived for 200 years.
The method of plastination, a technique to preserve animal and human tissue by which body fluids and fat are replaced with synthetic materials such as silicone resins or epoxy polymers, is chosen as it can keep the specimen almost the same, leaves no odor and is sustainable.
The legs and nails of the turtle. For the turtle to be plastinated, two German experts were invited to Vietnam three months after she died. In August 31 last year, Vietnam assessed their work and concluded that the "the plastinated specimen retains the same charisma of the turtle when alive."
Scars on the turtle’s shell and legs have been kept intact. Before her death, the turtle had been surfacing several times due to the lack of oxygen in the water caused by pollution.
In November 2017, Hanoi announced a VND29 billion ($1.28 million) project to clean up the lake. The Hanoi Sewage and Drainage Ltd. said its surveys had found "serious pollution" in the lake, which is home to aquatic plants, invertebrates and fish.
The turtle’s reproductive organ.
Unofficial reports have said the Sword Lake used to be home to three giant turtles, but one had died a long time ago. The latest death was in 1967 and the carcass of that turtle is now placed next to the newly plastinated one.
For preservation, the plastinated specimen should be kept at temperature under 25 degrees Celcius (77 degress Fahrenheit) and a humidity of 55 percent. It should also be shielded from direct sunlight, dust, and mildew.
The box where the plastinated turtle is displayed is made of toughened, anti-light and anti-flash glass is one centimeter thick, and equipped with air cleaning and humidity conditioning systems.
In July last year, China suggested a collaboration project to breed the Sword Lake turtle and Vietnam has welcomed it.