A rare but beautiful phenomenon, which is registered more than once in 10 years was surprised over the Grand Canyon in the USA. Dense clouds and thick fog created the illusion that the water passing through the canyon reached the top, near its peaks. It was created a second river from vapor.
In reality, it was about a thermal inversion. Basically, the temperature recorded at ground level was lower than the altitude, though normally the things are inside out.
Such a phenomenon is pretty rare, so the Grand Canyon was the scene of a show surprised by the employees of the park.