Where in the world?
The flag of Oman features a red vertical band on the hoist side that takes up about one-fourth the width of the field, and three equal horizontal bands of white, red and green adjoining the vertical band. At the top of the vertical band is the white emblem of Oman.

Oman

Native Name: عمان

Population: 5,106,622

Region: Asia

Sub Region: Western Asia

Capital: Muscat

Currencies: Omani rial

Top Level Domain: .om

Languages: Arabic

Border Countries: Saudi ArabiaUnited Arab EmiratesYemen