7 of the most stunning natural phenomena around the world

Fire rainbows, also known as circumhorizontal arcs, are stunning optical illusions that resemble a rainbow-colored flame in the sky. They occur when sunlight passes through ice crystals in high-altitude cirrus clouds. These beautiful displays are quite rare and fleeting, as they need a specific combination of conditions: the sun must be at least 58 degrees above the horizon, the clouds must be in the correct angle and position, and the observer must be in the right place. Fire rainbows are most commonly seen during the summer months in the mid-latitudes of both the northern and southern hemispheres.