How to properly design a database with cities and regions?

Question

MySQL

Good afternoon, dear forum users, please tell me how to properly design a mysql database with cities and regions.
The task is the following, to organize a filter by city and district as on Avito.
And a related question, in fact, where can you take cities with districts, bring them into the database with your hands, or are there ready-made bases?
Site on codeigneter framework.

Answer 1

There are ready. They are called KLADR and FIAS.