Curbin' the Urban

These are the countries that contain only one urban area, and that at the lower end of the population count (500,000+)

Albania
Bahrain
Benin
Central African Republic
Croatia
Djibouti
Eritrea
Gabon
Gambia
Jamaica
Kyrgyzstan
Laos
Latvia
Lithuania
Macedonia
Mauritania
Moldova
Nicaragua
Norway
Oman
Qatar
Sierra Leone
Tajikistan
Trinidad and Tobago
Turkmenistan