A cashel is a roughly circular stone fort, typically of early medieval date, and the structures that sheltered inside them were often clochans, the corbelled drystone huts whose overlapping stone courses curve inward and upward to form a roof without a single piece of mortar. What makes Glenderry worth attention is not one such structure but the possibility of five of them, clustered together inside the same enclosure.

Research by Toal, published in 1995, identified five depressions within the interior of the cashel, describing them as suggesting beehive huts built of drystone walling. They are all sub-circular in plan and vary in diameter between 4.8 metres and 8 metres, a range that hints at different functions, some perhaps for sleeping or storage, others potentially larger communal spaces. The depressions are what remains when a corbelled structure collapses inward over centuries, the stones gradually settling into the footprint of the walls. That five such features appear together within a single cashel points to a small but organised early settlement, the kind of enclosed monastic or farming community that once punctuated the Kerry landscape.