This ancient stadium, built during the 4th century BC, is said to be one of the best-preserved of its kind. Once seating up to 6500 spectators, this place was used not only for athletic events during the Pythian games but also as a concert venue. The surroundings of this stadium are simply spectacular.
Wikipedia https://en.wikipedia.org/wiki/Stadium_of_Delphi
Address 32004, Greece
Coordinates 38°28'57.414" N 22°29'52.418" E