This site offers a set of 3-d reconstructions with a CAD program of the major monuments of Constantantinople, as they appeared around 1200 (a few years before the city was sacked during the Fourth Crusade). According to its introduction, Byzantium 1200 is the creation of an independent researcher (for whom no name is given), in collaboration with Albrecht Berger, then of the Deutsches Archäologisches Institut Istanbul, now Professor of Byzantine Studies at the Ludwig-Maximilians-Universität Munich.
Each building was reconstructed using a combination of earlier sketches, ancient and medieval reports, and, in some cases, original on-site surveying in Constantinople. The reconstructions consist of 3-d renderings from one or more perspectives, although there is no standard of presentation. Each site is marked with a yellow dot displaying its location in the city, but unfortunately there is no interactive map which displays buildings simultaneously, producing the impression of a disconnected series of monuments (though see this video). Buildings from Late Antiquity are well represented on this site, but they are shown without the “wear and tear” and spoliation which they invariably suffered by 1200 CE; thus, in practice the site’s subtitle means that all additions to the original structure up to that point in time are recorded. So, for example, the Church of the Holy Apostles has not only the original construction of Constantine, but also the substantial expansion project of Justinian. Other highlights of the site include the Great Palace and the Hippodrome, both of which are presented with views of their numerous components.
Byzantium 1200 is a ground-breaking site: it is a unique tool for visualizing the Late Antique and Medieval monuments of the city, always a challenging endeavor for the informed scholar/tourist despite the inherent interest of the structure of Ottoman and modern Istanbul and its deep connections to the Byzantine period. However, it cannot be used as a reference for research, because that none of the sources for a given monument’s reconstruction are listed.