What is the locality of the country Macau?

Macau is not a country, it is both the name of the Special Administrative Region of China and of it's main city. It lies across from Hong Kong in the Pearl River Delta.
Macau was a Portuguese overseas territory from 1557 until 1999, nowadays it runs on a city state model with it's own flag, currency, laws, international border and official languages. (Chinese and Portuguese, plus the mixed creole called Patuรก)