During the Anglo-Boer War the British built 8000 blockhouses at vital points, and this relic is the southernmost of a chain protecting the rail link to the north. It is prefabricated from stone with cement gun outlets, an ironwork lookout and a corrugated iron .
The standard pattern blockhouses were constructed of mortared stonework or reinforced concrete and measured 6,1 m square externally. They were almost always three storeys high, the ground floor typically being used as a storage area, the first floor as a living area and the second floor for observation over the countryside under a pyramid-shaped timber and corrugated iron roof, with small gabled extensions over the steel machicouli galleries. The latter were cantilevered out from the walls at two diagonally opposite corners to allow flanking fire along the wall faces in the case of an attack.
The ground floor had two loopholes per wall. The entrance door was situated on the first floor, which also had three windows (one in the centre of each wall) and there were two loopholes on either side of these openings. The second floor had four loopholes at low level in each of the parapet walls, the gap between the top of the parapet and the eaves of the roof being closed by canvas 'drops', which could be rolled up in fine weather. The walls of the blockhouse were 900 mm thick on the ground floor, 600 mm on the first floor and 450 mm on the second floor, the internal offsets carrying the upper timber floors.
Access to the blockhouse was by a ladder to the first floor, which could be drawn up inside in the event of an attack. Similar ladders inside the building gave access to the floors above and below. The roof was fitted with galvanised gutters which discharged rainwater through internal downpipes to circular corrugated iron water tanks on the ground floor, in the two corners opposite those occupied by the machicouli galleries. The tanks were topped up regularly in dry weather, by train (in the case of railway blockhouses) or by water carts brought in from adjacent garrison towns. Food, ammunition, mail, etc, was delivered in a similar manner. The stable-type door, window shutters, loophole plates and galleries were all made of 10-13 mm thick steel plate,(9) each with a 100 x 75 mm, or a 100 mm circular, loophole through which to fire.