This photo shows a section of the Parthenon on the Athens Acropolis and the Doric Order of the structure is clear with its distinctive Frieze sitting above the column capital. However, this order exists in both the Greek and Roman forms so which type is it? It might be obvious in this case, given the location of the structure, but both forms are quite different when the detail is considered.
Whilst we are not about to enter the debate about the multitude of differences here, two to remember are that the Greek form never has a base and the Triglyphs on the Frieze (the rectangles with vertical lines) finish tight into the external corner, like the photo. The Roman form always has a base and the last Triglyph on the Frieze at the corner is centred on the last column rather than the apex of the corner.