Where in the world?
The flag of Tunisia has a red field with a white circle in the center containing a red crescent and a red five-pointed star.

Tunisia

تونس

Population: 11,818,618

Region: Africa

Subregion: Northern Africa

Capital: Tunis

Top Level Domain: .tn

Currencies: Tunisian dinar

Border countries

The flag of Algeria has two vertical bands of green and white, with a red crescent and star centered over the boundary between the colors.

Algeria

Population: 44,700,000

Region: Africa

Capital: Algiers
The flag of Libya has a horizontal triband of red, black, and green with a white crescent and star centered on the black stripe.

Libya

Population: 6,871,287

Region: Africa

Capital: Tripoli