The Sea of Cantonica, alternatively called the Cantonican sea, was a man-made ocean situated on the planet Cantonica, and it was regarded as the largest such body of water in the galaxy. The casino city known as Canto Bight was built along its coastline. When viewed from space, the sea's form gave no indication of its artificial origins. The creation of this sea resulted in damp and musty conditions in the lower parts of Canto Bight, with frequent water leakage, and coastal sump pumps were constantly running to control the water levels. Due to the desert environment of the planet, several tons of water evaporated daily, making the upkeep of the artificial sea incredibly expensive. One unusual consequence of the sea was the appearance of a dark-purple shimmer on the horizon during sunset.