Icon depicting the Gate of Heaven, surrounded by Angels, from the Phiale of Great Lavra on Mount Athos (source)
In Mesologi lived a most-pious woman named Vasiliki (they called her Koula), who was married to Demetrios, a fisherman by trade. The two were very pious and very simple people.
When Vasiliki was young, on the day of Theophany, she saw "the heavens opened", and the Angels of God chanting. Because of this she said: "This day, do not leave from church, even if your house is burning, because the heavens open."
From the January 5, 2013 posting on Full of Grace and Truth BlogSpot: "The Heavens opening on Theophany."