The 'golden' in the name comes from the warm, sunlit patch of feathers on the back of its head. The rest of the bird is mostly dark brown. From below, when it is flying, you can see lighter patches on its wings and tail. It looks huge in the air, with wide flat wings that don't need to flap often.
Golden eagles can see incredibly well. Scientists think their eyesight is about eight times sharper than ours. From hundreds of metres up, they can spot a rabbit moving in long grass. They hunt by gliding for hours on warm rising air, watching the ground far below, and then diving fast to grab their meal in long curved claws called talons.
Their nests are giant. A pair of golden eagles will build a nest of sticks on a cliff or in a tall tree and add to it each year. After many years, the nest can be over 2 metres across and weigh as much as a small car. Eagles often come back to the same nest year after year.
On the Mexican flag, the golden eagle stands for one of the oldest stories of the country. The Aztecs say their wandering people knew where to build their city when they saw an eagle landing on a cactus, holding a snake. That is exactly the picture on Mexico's flag today.