Where in the world?
The flag of South Korea has a white field, at the center of which is a red and blue Taegeuk circle surrounded by four black trigrams, one in each corner.

South Korea

Native Name: 한국

Population: 51,780,579

Region: Asia

Sub Region: Eastern Asia

Capital: Seoul

Currencies: South Korean won

Top Level Domain: .kr

Languages: Korean

Border Countries: North Korea