Avalon (planet)
From Tardis Wiki, the free Doctor Who reference
Avalon, a planet with six moons, was discovered near the end of the Earth Empire. Once home to an advanced race, it was colonised by humans, who set up a nation named Elbyon, which was able to use what was believed to be magic by accessing the planet's old network of nanomachines, which allowed those with the right level of skill to manipulate the world around them. The First Doctor visited Avalon circa 3025, where his actions resulted in the destruction of the nanite network to stop a powerful 'sorcerer'. (PROSE: The Sorcerer's Apprentice)
Using nanomachines and a nova trigger, they attempted to force the empire's planets to stay together towards the end of the empire, though they were unsuccessful. (PROSE: The Dark Path)
