microcosm
noun /ˈmaɪkrəʊkɒzəm/
  /ˈmaɪkrəʊkɑːzəm/
Idioms - a thing, a place or a group that has all the features and qualities of something much larger
- The family is a microcosm of society.
 
Word OriginMiddle English: from Old French microcosme or medieval Latin microcosmus, from Greek mikros kosmos ‘little world’. 
Idioms 
in microcosm 
- on a small scale
- The developments in this town represent in microcosm what is happening in the country as a whole.