It is widely referred to simply as the City ( often written as just `` City '' and differentiated from the phrase `` the city of London '' by capitalising `` City '' ) and is also colloquially known as the Square Mile , as it is 1.12 sq mi ( 2.90 km2 ) , i.e. , just over 1 sq mi , in area .
Often referred to as the City , or the Square Mile , it is just over one square mile , 1.12 sq mi ( 2.90 km2 ) in area .