While you may not be able to visit many of the sites and monuments discussed in this class, you can read and reference the "primary publication" that fully documents the site/monument. These are often included in "site reports" or a "final" publication of a site. Smaller objects (such as scupltures) may be documented in a journal article as its "primary publication."
Here is a beginning strategy to determine the primary publication for your subject. ...keep notes of articles or books that you use to locate the primary publication, as these may be useful in your preliminary bibliography of specialized literature.