The primary focus of our group is on the "history of civilization", a topic without a fixed category at Yahoo!
Because of our recent prevailing interest in prehistoric mapping and land survey, we have placed our group in the Yahoo! category of "Geography", broadly defined at the Wikipedia as "the science that studies the lands, the features, the inhabitants, and the phenomena of the Earth", also in a historical context.
We of course also explore ancient cultures and whatever fits under the broad umbrella of ancient human achievement.
At Flickr we have founded Archaeology Travel Photos
, which has over 2000 members and about 40000 photographs, and Megalithic Sites of the World
, which has over 500 members and over 4000 photographs (as of March 2013).
Our group operates primarily as a newsletter and not as a chat group.