Though I have never attended the miraculous ceremony of the Holy Light in Jerusalem which takes place annually on Holy Saturday afternoon, I once did have the blessing of seeing the Holy Light when I was in Athens in 1991, and was told of a miracle performed by the Holy Light not in Jerusalem, but in a tiny chapel in Athens.
After two months of pilgrimages to various holy shrines throughout Greece, my final day arrived and I was staying with my Uncle and Aunt in Glyfada, Athens. My Aunt Sia decided to buy me a gift before going home, so she took me across the street to the home of an iconographer whom she knew in order to buy me two hand-painted icons. We arrived at the home of this older couple and when I walked in the entire house was filled with icons, which was obviously also their studio. My aunt told me to choose two icons, so I picked one of Christ at Jacob's Well with St. Photine and another of All New Martyrs Under the Ottomans, both of which were very beautiful.
The couple whom we bought the icons from were a very devout and welcoming couple and were most impressed by the extensive pilgrimage I took, being only 15 years old at the time. They decided therefore to take me to a chapel nearby of which they were caretakers and is little known in Glyfada, dedicated to Saint Barbara but belonging to the Brotherhood of the Holy Sepulchre in Jerusalem. After venerating the icons they showed me a spot which contained a glass bowl of oil in which was lit a small fire. This fire they told me came from Jerusalem a few years prior when monks brought the Holy Light to Athens. Since then this fire burned perpetually.
When I asked how they kept the fire burning perpetually for so long, they told me about a miracle. They said that since they were the only caretakers of the chapel, they always took care of the Holy Light to make sure it never extinguished. One year however they went to go visit family abroad for more than a few weeks, and when they returned the Holy Light had extinguished. With sorrow they decided to reignite the oil lamp anyway, so they grabbed some oil and refilled the bowl. As they refilled the bowl the Holy Light spontaneously lit again without having to be reignited. Since then they always made sure to keep the fire going.
See more photos of the chapel here.