Where in the world?
The flag of Vietnam has a red field with a large yellow five-pointed star in the center.

Vietnam

Việt Nam

Population: 97,338,583

Region: Asia

Subregion: South-Eastern Asia

Capital: Hanoi

Top Level Domain: .vn

Currencies: Vietnamese đồng

Border countries

The flag of Cambodia has a blue field with a red stripe in the center and a white depiction of Angkor Wat in the middle.

Cambodia

Population: 16,718,971

Region: Asia

Capital: Phnom Penh
The flag of China has a red field with five yellow stars in the top left corner, one large star surrounded by four smaller stars in a semicircle.

China

Population: 1,402,112,000

Region: Asia

Capital: Beijing
The flag of Laos has three horizontal stripes of red, blue, and red, with a white disc in the center of the blue stripe.

Lao People's Democratic Republic

Population: 7,275,556

Region: Asia

Capital: Vientiane