How did the Greeks design and build their classical monu ments, which in the course of time have repeatedly been regarded as exemplary? What skills did the erec tion of these imposing marble edifices require? On what aesthetic theory were they based? The answers to these ques tions were sought by archaeologists for more than 200 years. Although it is known that the Greek architects themselves wrote detailed explana tions of the conception and construc tion of their buildings, none of these written works has survived to the pres ent day. No other sources reveal what kind of construction plans (if any) were followed by the ancient builders. In the absence of any descriptions of tem ple" blueprints" scholars had no idea where to look for them. Actually the blueprints were under the archaeologist's nose all along. I recently discovered an entire archive of construction plans still in place at a site that has been under study since the turn of the century: the famous ruin of the Temple of Apollo at Didy ma, south of the present-day Turkish town of Sake.

During a tour through the lands of classical antiquity that the German Archaeological Institute sponsors an nually for young archaeologists, I took a side trip to the temple of the Didy maean Apollo. It was on that excur sion in October, 1979, that I first came across many finely etched lines on some of the temple walls. What first sparked my curiosity during that casu al visit to Didyma became the subject of a major archaeological project: it developed that the lines trace out the design of various temple structures. The incised blueprints cover an area of hundreds of square meters and con stitute the most extensive and most complete set of plans that have come