Deathwater Island

Deathwater Island (briefly called Goldwater Island) is a location in the Eastern Ocean. It is a low-set, but somewhat hilly island about twenty acres in size. It is home to a magical pool that can turn anything and anyone that touches it into pure gold. One stream feeds out of this pool into the ocean, while another more sheltered one originates from somewhere else on the island. The weather is somewhat unsettled, prone to sudden rainstorms and fresh but somewhat strong breezes. It is also fairly desolate, with only a large quantity of heather being the main sign of life.

Apart from its enchanted pool, the island's most notable feature was its role as the tomb of a Narnian lord. Various rusted weapons, coins, and pieces of armour were scattered around the heather, and at the bottom of the pool lay a statue of pure gold. The statue was none other than Lord Restimar, who had happened upon the pool during his search for the end of the world, and had accidentally turned himself into gold when he entered the pool to swim.

The island was one of the numerous islands visited by Caspian X and his crew during his voyage aboard the Dawn Treader, where they stopped to refill their water casks. Drinian almost took water from the stream leading to the cursed pool, but was reluctantly diverted to the other river when his boatmates objected to the rain. After filling their empty casks, Caspian, Lucy and Edmund Pevensie, Eustace and Reepicheep decided to explore the interior of the island, where they came upon the enchanted pool.

Having found the remains of Narnian armour and coins in the brush, the group suspected that the island was where another Narnian lord had met his end, but did not immediately connect the relics to the golden man in the pool. The group suspected the water made everything in it merely look like gold, but this theory was soon dispersed after Edmund tried to see the depth of the pool with Caspian's hunting spear. Edmund soon noticed the water's effect on his boots, which had turned the toes of his boots to solid gold, and they all realised the 'waters' effects on objects. Reepicheep and Lucy were understandably shocked at both the man's fate and their own close call, but Caspian decided to test the pool's effect with a sprig of heather, and soon found himself with a perfect golden replica of the plant.

Overwhelmed by the thought of inexhaustible riches, Caspian called the island "Goldwater", and prepared to draw his sword on Edmund when the latter attempted to contest his authority as King, and as ruler of Goldwater Island. The brief vision of Aslan, which appeared on the hilltop above them, immediately made them realise the foolishness of their actions. All memory of the incident was then lost to the group, save that they had found one of the seven Narnian lords, and that the island was under some sort of horrible enchantment.

Reepicheep, by means of an unknown inspiration (probably Aslan), suggested the name of "Deathwater" instead, and Caspian took the name.

Film Adaption
In the Voyage of the Dawn Treader film, Deathwater Island and Dragon Island were one of the same. Also, the island was a volcanic wasteland, with no plants or heather, like how it was described in the book.