Uruguay’s national flag features a yellow sun with 16 alternating straight and wavy rays.
The Sun of May appears in a white canton at the hoist, above nine horizontal stripes that alternate between white and blue. Its face and rays represent the May Revolution, the independence movement that began in the region in May 1810. The alternating ray styles are a defining detail of the emblem.
Uruguay’s first national flag was adopted in 1828, after the country gained independence. The current nine-stripe arrangement dates from 1830, when the number of stripes was reduced from the original design. The nine stripes represent Uruguay’s original departments, or administrative divisions.
Argentina’s flag also displays a Sun of May, so the two flags are frequently confused. Argentina uses three horizontal bands and places its sun in the center; Uruguay places its sun in the upper hoist canton and uses nine stripes.