The sanctuary of Delphi was the place where oracle of Apollo spoke, and was the site of the omphalos, the 'navel of the world' - Delphi in the 6th century BC was the religious centre and symbol of unity of the ancient Greek world. The site is situated on multiple terraces along the slope of Mount Parnassus in lower central Greece - the layout is a unique artistic achievement, situated in a magnificent natural setting which is still intact.
This photo shows Tholos, a circular building in Doric order, built around 380 BC at the sanctuary of Athena Pronaia, located approximately half a mile from the main ruins. Its function is unknown but almost certainly of main importance, judging from the fine workmanship and the high-standard relief decoration.
Many many thanks to Despina, for such a fine choice of a card and stamps! I don't think I can ever get enough of ancient sites, so much history :)