The Tholos of Delphi, an ancient structure in the Sanctuary of Athena Pronaia in Delphi, Greece.
Originally domed, the Tholos (circular temple) of Delphi would have been seen by a visitor before they reached the Temple of Apollo (thus the sanctuary’s appellation Pronaia, “before” the temple). It originally had twenty Doric columns on its exterior diameter (three have been reconstructed for modern visitors), and ten Corinthian columns on its interior diameter.
The Tholos was built between 380 and 360 BC, and badly damaged in antiquity — first by earthquakes, and later by people salvaging its stonework for building material. Its original purpose is currently unknown.
Olympus E-M1III, M.Zuiko 8-25mm f/4 Pro lens
ISO 200, 25mm, f/7.1, 1/200 sec