There are 7 celestial islands mentioned in the Purana. These seven island continents form concentric circles. There are 7 cosmic oceans and these oceans are formed from different types of liquids and separate the island.
Names of the 7 celestial islands and Names of the 7 cosmic oceans are
Lavana sagara ocean of salt water that surrounds Jambudvipa
Ikshu sagara ocean of Sugarcane Juice that surrounds Plakshadvipa
Suroda sagara ocean of Wine that surrounds Shalmalidvipa
Sarpi sagara ocean of Ghee that surrounds Kushadvipa
Dadhi sagara ocean of curd that surrounds Kraunchadvipa
Kshira sagara ocean of Milk that surrounds Shakadvipa
Svadu sagara ocean of fresh water that surrounds Pushkaradvipa
Mount Meru is situated at the exact center of Jambudvipa. It is a golden mountain known as the cosmic axis that supports the heavens and links the earth to the sky.