Вы можете использовать базу данных городов / стран в формате Microsoft SQL / Mysql отсюда -
http://myip.ms/info/cities_sql_database/World_Cities_SQL_Mysql_Database.html
Структура таблицы городов / стран -
CREATE TABLE cities (
cityID int NOT NULL,
cityName varchar(50) NOT NULL,
stateID int NOT NULL,
countryID varchar(3) NOT NULL,
latitude float NOT NULL,
longitude float NOT NULL,
PRIMARY KEY (cityID),
UNIQUE (countryID,stateID,cityID)
);
CREATE TABLE countries (
countryID varchar(3) NOT NULL,
countryName varchar(52) NOT NULL,
localName varchar(45) NOT NULL,
webCode varchar(2) NOT NULL,
region varchar(26) NOT NULL,
continent varchar(15) NOT NULL,
latitude float NOT NULL,
longitude float NOT NULL,
surfaceArea float NOT NULL,
population int NOT NULL,
PRIMARY KEY (countryID),
UNIQUE (webCode),
UNIQUE (countryName)
);