Where in the world?
The flag of Belgium has three vertical bands of black, yellow, and red.

Belgium

België

Population: 11,555,997

Region: Europe

Subregion: Western Europe

Capital: Brussels

Top Level Domain: .be

Currencies: Euro

Border countries

The flag of France has three vertical stripes of blue, white, and red.

France

Population: 67,391,582

Region: Europe

Capital: Paris
The flag of Germany has three horizontal stripes of black, red, and gold.

Germany

Population: 83,240,525

Region: Europe

Capital: Berlin
The flag of Luxembourg has three horizontal stripes of red, white, and light blue.

Luxembourg

Population: 632,275

Region: Europe

Capital: Luxembourg
The flag of the Netherlands has three horizontal bands of color: red on the top, white in the middle, and blue on the bottom.

Netherlands

Population: 17,441,139

Region: Europe

Capital: Amsterdam