Duckling Lake, also known as Summit Lake, is a lake on the mountainside. Summerstone Castle is on the shore of the lake and is a very popular place to see on Wuhu Island. Duckling Lake itself is also a popular spot, especially with canoeists. The lake gets its name from the population of Wuhu Ducks that live in the lake and on its shores. There is also a variety of Cichlid (a fish) species in Duckling Lake. One, the Wuhu Cichlid, is a species only found on Wuhu Island, although its population is large.

In Wii Sports Resort, Duckling Lake hosts the Canoeing activities. It is also part of stage 8 of Swordplay Showdown, the Cliffs. Cyclists also pass by it on the 5th race in Cycling.