Building A was round (outer diam. 6.2 m, max. preserved height of the remains c. 2 m; Fig. 1) and had a central circular column (diam. 2.5 m) surrounded by a corridor (width 1 m). The peripheral wall (width c. 1 m) is double-shelled. The outer shell was founded on bedrock and constructed of large fieldstones, their outer face dressed, and retaining fragments of light gray plaster. The internal shell was constructed of rows of triangular cells. Three–four rows survived (height above the floor 0.2–1.5 m; Fig. 2), and between them there is a packed fill of small stones and mortar. The outer face of the central column, facing the corridor, is similarly constructed. Four–five rows of the triangular cells (height over 1.9 m) survived. Light colored lime mixed with soil can be seen on the walls of the cells and between the stone courses. The floor of the structure was rock-hewn, but not leveled, and covered with a layer of tamped mortar. The floor was overlain with a layer of loess (thickness c. 0.25 m) which was in turn covered with a layer of dark soil (thickness 0.05–0.10 m) containing large quantities of organic finds, including rodents bones. These successive layers were deposited over a long period, after the site was abandoned and until the structure collapsed. Evidence of the collapse was discerned in the fallen stones that were excavated at the top of the building, inside the corridor, and on the deposit of dark soil. Large flat stone slabs that were discovered in the collapse, apparently roofed the structure. Amongst the collapsed stones were architectural elements, including a window- or door-jamb, that was likely installed higher up in the dovecote; a fragment of a column drum, probably in secondary use; and part of a stone slab with an engraving of a cross framed by a circle. The few pottery sherds that were found in the collapse and the underlying accumulations were of no assistance in dating them, but it seems that the building was abandoned in an orderly manner before it was destroyed. A fifth century CE coin, possibly evidence to the time of construction or subsequent renovation, was found in a trench that was excavated outside the building, near the foundation of the wall that was set on the bedrock. A random secondary burial that evidently dates to the Ottoman period was found in the upper part of the building, above the collapse.
Building B was square (4 × 4 m, preserved height 1.5 m), and constructed on a rock outcrop on which several rock engravings were identified, including a cross. Two trial trenches were excavated on both sides of the eastern wall, inside and outside the building (width 0.7 m, height 1.4 m). A single row of triangular cells survived on the upper inside part of the wall (Fig. 3). The cells were built of stone slabs with a fill of small stones and soil between them. A section through the building exposed two cubicles (northern and southern), with a partition wall (width c. 0.5 m, height 0.8 m; Fig. 4) between them. The partition wall was constructed of small and medium stones, with a row of triangular cells at the top, similar to those in the outer wall. Thick gray plaster survived on the walls, and numerous plaster fragments were discovered in the accumulations that were excavated in the interior space of the building. The building had a tamped-earth floor laid over a level of small stones, set in the virgin soil overlying the bedrock. Smooth stone slabs on the floor of the southern cubicle seem to have been placed there to level the floor. The accumulated deposit inside the cubicles contained large quantities of stones from the collapsed walls of the building, slabs from the dovecotes and numerous fragments of terra cotta pipes that were used for nesting in the upper parts of the dovecote. The debris was also rich in organic material that included pieces of wood and short twigs (probably nesting material), numerous botanical finds, dove bones and droppings. This accumulated debris sealed below it a compacted gray layer that was identified as dove droppings and was left in situ on the floor of the two cubicles. Above the layer of droppings were two articulated skeletons of doves. When excavated the rich organic finds included dove bones, eggshells, bits of vegetation and a few fragments of terra cotta pipes. Four levels of crushed chalk over a level of small stones overlying the bedrock were documented in the excavation of a trench to the east, outside the building. A coin, probably dating to the Byzantine period, which was found in the crushed chalk, indicates the foundation date of the building, or the date of a renovation of its exterior.
Two principal phases (I, II) were identified in the excavation. The buildings were used for their original purpose in Phase I and were abandoned in Phase II. The finds in Building A indicate a gradual destruction after its abandonment; whereas the finds in Building B indicate a single, sudden destruction episode, and the level of manure on its floor remained in situ. Above this layer were complete skeletons of doves and accumulated bird droppings. The shape of the buildings, the cotes in their inner walls, and particularly the archaeozoological finds indicate that the structures were used as dovecotes, testifying to dove-raising at the site. The dovecotes were dated to the Byzantine period and it seems that the buildings were not constructed prior to the fifth century CE. The dovecotes give evidence to specialized economy of dove-raising in the northwestern Negev during the Byzantine period. A similar phenomenon was identified at Shivta and other sites in the region (Hirschfeld and Tepper 2006). The location of the dovecotes in the agricultural areas of the site may allude to their purpose in the context of farming. Animal manure was a necessary and essential product for carrying out specialized agriculture in the northwestern Negev. Of the various animal and fowl droppings that were used in antiquity, dove manure was considered the richest and best quality (see in detail Tepper 1986), and this is probably the reason for the establishment of dovecotes near Horbat Sa‘adon.