A fata Morgana, named after Morgan le Fay, the faery shapeshifting half-sister of King Arthur, is a mirage, an optical phenomenon which results from a temperature inversion. Objects on the horizon, such as islands, cliffs, ships or icebergs, appear elongated, like "fairy tale castles".
In calm weather, the undisturbed interface between warm air over cold dense air near the surface of the ground may act as a refracting lens, producing an upside-down image, over which the distant direct image appears to hover. Fata Morgana are usually seen in the morning after a cold night which has resulted in the radiation of heat into space. The first mention of 'Fata Morgana' in English, in 1818, referred to such a mirage noticed in the Strait of Messina, between Calabria and Sicily. It is common in high mountain valleys, such as the San Luis Valley of Colorado where the effect is exaggerated due to the curvature of the floor of the valley canceling out the curvature of the Earth. They may be seen in Arctic seas on very still mornings.
Fata Morgana was taken as the title of a crime novel by Agatha Christie.
Fata Morgana is an annual review since 1996, publishing prize-winning short stories in Italian, with the themes "doubles, opposites, enemies, lovers."
The Fonte di Fata Morgana ('Fata Morgana's Spring'), locally called the Casina delle Fate ('Summerhouse of the Fates'), at Grassina, not far from Florence in the commune of Bagno a Ripoli, is a small garden building, built in 1573-4 as a garden feature in the extensive grounds of the Villa "Riposo" of Bernardo Vecchietti on the slope of the hill called Fattucchia.
It is among that group of artificial garden grottoes and Nympheums made for private gardens, and less well known than more visited examples, such as in the Boboli Gardens or the Medici villa at Pratolino. The Fonte di Fata Morgana is enriched with sculptures in the manner of Giambologna. Recently acquired by the Comune di Bagno a Ripoli, the Fonte della Fata Morgana, is being meticulously restored.