Utter East

Utter East was the eastern-most edge of the flat, circular world of Narnia. It was a notable section of the End of the World, since it is from here that the sun would rise.

Utter East ended with the waters of the Silver Sea rising up into a standing wave, over thirty feet high, that sat at the edge of the world, like a stationary yet watery barrier making a wall around the rim of the world. The sun rose each day from behind this "standing wave", which is why the sun appeared closer the farther east one was. The only land at the Utter Eastern End of the World was a small plain of green grass just slightly higher in elevation to the Silver Sea itself. Beyond this grass plain lay Aslan's Country which could be dreamily perceived atop a high mountain, visible beyond the other side of the glass-like Narnian sky, at the very exact edge of the world.

The Utter East was also marked by "sweet" - i.e. not salty, but drinkable - water. This fulfilled the prophecy which Reepicheep recited at the beginning of the book: "Where the waves grow sweet, there is the Utter East." The sweetness of the water was first discovered by Reepicheep when he dove over the side of the Dawn Treader to answer the challenge of the king of the Sea People. It isn't clear from the text just when the Dawn Treader entered the area of the sweet water

The "sweet" water was more than just not salty - it was described by those who drank it as "liquid light". It sustained the crew of the Dawn Treader so they needed to neither eat nor drink anything else, and enabled them to bear the light which grew increasingly intense as they drew near the eastern edge of the world.