Classified simply as a house of indeterminate date, it occupies that particular category of monument where the basic fact of survival has outpaced any detailed understanding of origin, function, or the people who once occupied it. The label "indeterminate date" is not evasiveness; it reflects a genuine gap, the kind that appears when a building defies easy classification by period or style, or when fieldwork has not yet produced the dateable materials that would anchor it more firmly in time.

Annagh Hill sits in a part of Connacht where the landscape carries layers of settlement reaching back thousands of years, and isolated structures of uncertain age are not uncommon across the region's upland terrain. Without further detail in the available record, it is not possible to say whether this particular building belongs to the medieval period, the post-medieval era, or somewhere else along that long continuum entirely. What can be said is that it was considered significant enough to be formally recorded as a monument, which places it within a protected category under Irish heritage legislation, however quietly it may sit on its hill.