Maecenas presents a well-organized slide collection of Greco-Roman sites. Every site offers thumbnails and captions identifying the monument. The multiple views of monuments permits the viewer to see each monument from multiple vantage points. The site emphasizes architecture from Rome and Italy, but also includes Greece, England, and France. I have used slides from Maecenas for slide shows in my Latin and Roman archaeology courses.
Since these are scans from a 35 mm slide collection, many of the images are not as large nor show true colors as newer digital cameras are capable of.