Definitions

Utopia
1: an imaginary and indefinitely remote place
2: a place of ideal perfection especially in laws, government, and social conditions
3: an impractical scheme for social improvement
4: an imagined place or state of things in which everything is perfect. The word was first used in the book Utopia (1516) by Sir Thomas More.
The opposite of dystopia (Oxford Dictionaries)

Origin: based on Greek ou 'not' + topos 'place'

Dystopia
1: an imagined place or state in which everything is unpleasant or bad, typically a totalitarian or environmentally degraded one.
The opposite of Utopia (Oxford Dictionaries)