Nepal has the world's only non-quadrilateral national flag, shaped like two stacked triangles.
Nepal's national flag consists of two joined pennants, or triangular shapes, with a deep crimson field, a blue border, and white emblems of the moon and sun. The two triangles are commonly associated with the Himalayan mountains and with different branches of Nepalese political and religious traditions. Crimson is the national color, while blue represents peace.
The present constitutional design was adopted on 16 December 1962, although its basic double-pennant form developed from earlier royal and military banners. The flag's distinctive outline means it is not a rectangle or another four-sided quadrilateral, making Nepal unique among sovereign states.
The moon and sun symbols also express the hope that Nepal will last as long as those celestial bodies. Before 1962, the emblems had stylized facial features; the modern version removed them. The flag is defined in Nepal's constitution, which also specifies its proportions and construction method.