According to legend, Fata Morgana (Italian for fairy Morgan) was the half-sister of King Arthur. Morgan, who was said to live in a crystal palace beneath the water, had magical powers that could build fantastic castles out of thin air. Looking across the Straits of Messina (between Italy and Sicily), residents of Reggio, Italy, on occasion would see buildngs, castles, and sometimes whole cities appear, only to vanish again in minutes.
The Fata Morgana is a mirage
that tranforms a fairly uniform horizon
into one which rises vertical
ly above the horizon. This mirage occurs where the air
temperature increases with elevation above the surface. Thus, mirages like the Fata Morgana are often seen where warm air rests above a cold surface such as large bodies of water
Source: Essentials of Meteorology
by C. Donald Ahrens