Ho Guom

Also known as Hoan Kiem Lake, the Lake of the Returned Sword. The legend is similar to that of King Arthur: the Emperor Le Thai To received a sword from the turtle that lives in the lake. He used it to defeat the invading Chinese and then returned it to the turtle. Sightings of the turtle(s) are rare and make the front page of the newspapers, though many people believe they are mythical too. The water in the lake is very polluted, since it's in the centre of Hanoi, so some people think there must be a secret entrance that gives the turtles access to a cleaner environment somewhere. The species is known to exist elsewhere in northern Vietnam, but nowhere else close to Hanoi. They grow to a large size (I recall reading that an American tourist said she thought the flipper that appeared above the water surface was a shark's fin!). There is supposed to be a couple of very old ones in the lake, but nobody has ever seen any baby turtles. Certainly there's nowhere on the lake shore where a turtle could lay an egg. So unless they've got that mythical escape passage, I guess they will eventually become part of the legend anyway.

The pagoda on the island connected by the pretty red bridge is, from memory, called Ngoc Son (pearl mountain?) and is not related to the turtle story.