A Polis was the way a community was organized in ancient Greece. It consisted in:
- An Urban Center, which was the site where people lived. It was usually fortified with a wall in case of eventual conflicts. It had areas for public and private purposes, including places like a gymnasium or theatre. 
 - A Sacred Center, which was built and designated for religious purposes.
 
These centers were built in an Acropolis, which is a natural harbor surrounded by extensions of land. 
Each Polis was considered to be a city-state, due to the fact that each had its own political, judicial and legal structure.