No main entrance has buttresses on either hand on the outer side, possibly because these would have provided any attacking party with excellent shelter. All buttresses of such entrances are on the inside. Divisional entrances which have buttresses have them on the inside only.
The entrances through a wall of the earlier period are carried over the common foundation in the opening forming the steps, which were evidently constructed before the side walls were erected. These steps are large, broad, and high, and where intact look most imposing. Such entrances resemble stiles, as they are much higher than the levels of the floors on either side.
The entrances through an angular wall of a later period have steps which are not part of either side walls, but were built in after the entrance passage had been constructed, and these show poor workmanship and are very shallow, and recede only two to four inches. As the levels of the enclosures on either side have filled in over the original floors, such “cat-steps” have in some instances been built over the original large steps for the purpose of raising the floor of the entrances, seeing that the enclosures on either side had been filled in some feet above their original levels.
Directly opposite the main entrance of the “Outspan Ruins” is a large circular buttress, as if it were intended to divide any attacking party into small numbers.
CAUSE OF DILAPIDATION TO ENTRANCE BUTTRESSES
The entrance buttresses with portcullis grooves are in most instances comparatively small, some projecting only two to three feet towards the interior of the building, and these are built up against main and divisional walls, and are in point of construction altogether independent erections, there being no dovetailing or binding between the buttresses and the walls.
In some of the entrances the side lintels of slate, granite, and unworked soapstone beams have been found built into the portcullis grooves. In The Ancient Ruins of Rhodesia it was noticed that at several of the ruins therein mentioned stone side lintels were found in situ. The stone lintel posts in situ at Zimbabwe had not then been discovered. The tallest of such stone lintels at Zimbabwe is 8 ft. above the ground. The buttresses appear to have been built after the stone posts had been erected, for the walls at the sides of the lintel follow the irregularities of the side faces of the beams.
The great destruction which has occurred to these structures might possibly be accounted for by (1) the weight of the stone lintel on getting off the perpendicular, which would lever down the buttress into which it was built; (2) the foundations of buttresses are not so deep as those of the main wall up against which they were built; (3) when some later people, possibly natives, deliberately built up and blocked the entrances they might have used the blocks of these buttresses for their building material; (4) the passage-way between each pair of buttresses being so very narrow, damage could easily have been wrought by ordinary traffic; and (5) the main walls are much higher than the summits of the buttresses, and the walls on either side of the entrances being always more dilapidated on the summits, the falling of huge masses of masonry on to the buttresses immediately below might have effected their destruction.