According to legend, Hoan Kiem Lake is where Emperor Le Loi returned his magic sword to the Golden Turtle. At the northern end of the lake is an islet which stands the Turtle Tower (Thap Rua), which honors the turtle that still guards the sword of Le Loi. Sightings of the lake’s rare enormous soft-shell turtle named, Cu Rua (great-grandfather turtle) is believed to bring good luck. Unfortunately, it died in 2016, bringing the species one step closer to extinction.