Tsuki No Mizūmi

The Lakes of the Moon or Tsuki No Mizūmi (月の湖, meaning "lakes of the moon" in English) are three big lakes that circle the city of Atarashi Natsu.

The water of the biggest lake is really warm while in the others it is pretty cold. It is clean and not polluted.

Location
The lakes are located between the deadly desert and the thunder prairie.

Legends
A legend says that there is a temple of the island in the middle of the biggest lake but no one ever saw it because a giant sea serpent attacks the ships who try to get too close and there is a weird fog all around the island.

The temple is called Mangetsu by the nearby villagers because during the full moon, the temple seems to shine and is to be seen through the fog.