Here's my shot of the lake again. I had a panoramic shot, but in my brilliance, I accidentally deleted it off my iPhone.
There is a recurrent myth associated with this lake. It largely is connected to the turtles of the lake. In the fifteenth century, a Lê Lợi became emperor of Vietnam. Supposedly, he had this sword, which was taken by a turtle back into the lake. It's the reason why they call it in English, "The Lake of the Returned Sword." As least this is what I got out of Wikipedia. There is a temple on the lake called the "Temple of the Jade Mountain."
The Entrance to the place called in Vietnamese, Đền Ngọc Sơn, is rather ornate. There are a number of murals that remind me of Confucian and Taoist concepts. The temple itself has a person who is writing, what I believe to be fortunes on paper. He had a line going.
Additionally, the view of the lake is actually quite nice from this location. It is a tourist destination, as you had to pay an entrance fee.
The temple itself feels very Chinese. In fact, the one color that I would associate with the temple interior is red.
The turtle is preserved and on display.
Turtles or Tortoises have a significance to Vietnamese. It also seems to be a motif also connected to the Temple of Literature in Hanoi, which has a number of tortoises on display associated with various scholars. Supposedly, you rub the head to get some luck.
If you can tell, the lake has a very distinct green color. It is located in the heart of Hanoi, so I wouldn't recommend swimming in that water. Sort of like the idea of swimming in LA's Echo Park Lake or MacArthur Park. Not recommended.
It has a nice view of Hanoi.