Vista (Middle-earth)

In the fiction of J. R. R. Tolkien, Vista is a part of the atmosphere that surrounds the world of Arda before the cataclysm at the end of the Second Age. Vista forms the inner layer of normal air: above it is Ilmen, and above that Vaiya.

Vista is the breathable air, with in the top part the clouds, and in the lower parts the paths of birds.