Pacific Ocean

The Pacific Ocean (as it is known on Earth) or the South Sea (as it was referred to by Aslan) is the largest body of water on Earth, the original homeworld of all humans.

An un-named island existed in this ocean that was once inhabited (nothing is known of the island's original inhabitants, except they were a simple, primitive people). However, centuries later, the island was invaded by a shipload of pirates of unknown origins, who had been driven there by a storm. Once there, they did as pirates did, by killing the natives, save for the women, who they took as their wives, made palm wine, got drunk, and often quarreled and fought with one another.

During the Early Ages of Narnia, a group of 6 pirates on the island, together with their wives, were exiled by their own, fled to the centre of the island, where they found a cave to hide in. However, the cave had within it a rare chasm, or a chink, which existed between worlds, like a portal. From there, they were unintentionally transported to the then un-inhabited land of Telmar in the Narnian world, where they made their new home, and in time sired the Telmarine people.

After the Narnian Revolution, a majority of these Telmarines were sent back to Earth, to the isolated island in the Pacific Ocean, in which by then the pirate race had died out. According to Aslan, the Telmarines weren't allowed to go through that "doorway" again, as it would close immediately after they went through.

Trivia

 * The Pacific Ocean is 63.8 million square miles in area, making it the largest division of the World Ocean – and, in turn, the hydrosphere – which covers about 46% of the Earth's water surface, and about one-third of its total surface area, making it larger than all of the Earth's land area combined.