The flame that will burn during the London Games has been lit at the birthplace of the Ancient Olympics.   

An actress dressed as a high priestess used a concave mirror to focus the sun's rays and light a torch. Under the bright sunny skies Thursday, there was no need for the backup flame that was used during the final rehearsal for the Olympic torch lighting a day earlier.   

After the end of the choreographed ceremony, the priestess will hand over the torch to the first torchbearer, Greek swimmer and Olympic silver medallist Spyros Gianniotis.   

Gianniotis is the first in a line of 490 torchbearers to carry the flame across 2,900 kilometres on Greek soil before the flame will be handed over to the London Games organizers on May 17 in Athens' Panathenian Stadium, where the first modern Games were staged in 1896.   

In contrast to the two previous Summer Games, where the Olympic flame relay went around the globe, it will leave the U.K. only once, to pass though Dublin on June 6.   

The Olympic Games run from July 27 to Aug. 12