Initiated by the National Heritage Council of Namibia (NHC), Twyfelfontein Visitors Center was a conservation measure to address and cater to the rapidly growing numbers of visitors to a fragile World Heritage Site, home to one of the world’s richest collection of pre-historic rock engravings made by one of Africa’s oldest people – the San of Southern Africa.
Twyfelfontein, which means “Doubtful Fountain” in Afrikaans, indicates the importance of water in this barren environment. Located in the Northwest region of Namibia, the arid and remote site lies in a wide open valley flanked by cliffs of reddish-colored sandstone. The geography of this vast, flat, and vulnerable landscape is characterized by little rainfall, high temperatures, poor soil, and delicate vegetation. Essentially an open air gallery, the site’s 20,000 year old sandstone rock engravings were left exposed to both human and environmental impact. These engravings are considered national patrimony and for this reason, it was vital that the new Visitor’s Center not compete with the prehistoric rock art in any way.
The design brief addressed not only visitor’s needs, but also site protection of the walking routes and long-term management issues like potential income generating projects for the local community. After appointment through a competitive bidding process, architects Nina Maritz and Dennis Mc Donald positioned the building away from the rock art routes on the archaeologist’s advice, out of visual range, so that the visitor can imagine being in the prehistoric landscape, uncluttered by modern additions. This included removal of the existing visitors’ kiosk and shade structures in the valley below the routes, and using the rubble generated in the construction of the new centre.
The Center is in essence invisible to the public upon arrival. Walking along the path, the rounded organic form blends into its physical setting, announcing its presence with barely a whisper.
The building’s most important role is to prepare the visitor for an otherworldly experience in their engagement with the esoteric nature of the rock engravings. The spatial design and construction ferries the visitor through a series of spaces in psychological preparation for the guided walking routes to the actual rock engravings.
Cues were taken from natural features, landscape patterns, animal skeletons, and traditional San shelters. The plan evokes the shape of an animal curled in its death throes with its back arched. This metaphorical reference is overlaid back onto the site, and reinforces the interpretive program of the three stages of trance – a journey into the supernatural, where a period of physical endurance prepares the traditional healer or ‘shaman’ for trance.
In the first stage, resembling a malarial attack, retinal images called ‘phosphenes’ or ‘entoptics’ appear to the shaman in the shape of scrolls, spirals, circles and parallel lines that form abstract patterns. The shaman starts sweating and shivering. The second stage is called the ‘little death’, as it resembles the physical symptoms displayed by a wounded animal just before dying. The shaman feels weightless and levitates. In the third stage – that of full trance – the shaman leaves his/her body to merge with the visualized animal, enchanting it for hunting or ‘to make rain.’
Nina Maritz described the design process below:
The architectural challenge was to reflect these beliefs in a spatial way to make it easier for the visitor to internalize the theories behind the rock engravings. Our initial response was to find clues from the landscape – from curved overhangs forming shallow caves and square slabs leaning against each other to create narrow vertical slits as shelter. We then speculated as to what the original San would have done for shelter – rocks & caves or brushwood shelters, clad with grass bundles.
To effectively communicate the sensitively of the site, and instill respect for the environment in the users, a strong environmentally sustainable approach was essential. The only way to get water to this site was to truck it in. Also, the architects wanted the building to be able to adapt, if need be, to the next generation’s interpretation of rock art conservation and cultural values. This resulted in the decision to ensure that the project was waterless and reversible. The construction contains no cement and the building is completely removable and re-usable. The decision was also practical as there was no availability of labourers skilled in masonry construction.
Using gabion baskets (wire cages made on site from standard galvanized diamond mesh), solid masonry walls were constructed and filled with recycled rubble from the old kiosk foundations, and local loose stones gathered from different areas around the site so as not to leave scars on the landscape. Because it can be done with unskilled labour, this labour-intensive process brought much needed employment to the remote setting.
Caged gabion pebble paths also replaced previously designed concrete paths and steps, further limiting site intervention and avoiding need for concrete.
Steel, rather than timber, was used for the frame due to the short lifespan of timber in the extremely dry conditions, and prevailing termite infestations. It was erected before work started on the gabions, which allowed use of the steel structure as an aid for setting out the gabions. The structure’s supporting columns were secured in square gabion footing, some with tops flush with the ground level, and others with larger gabions creating seats in the dining area.
Entry into the building is through a narrow slit, and into the foyer occupied by the souvenir shop. Behind it the reception counter regulates circulation through the building where guides lead groups of up to ten people on walking routes. The dining area, served by a small kiosk acts as a lingering space for those waiting their turn.
The start of the walking routes is preceded by an area for information display leading to two ‘experience chambers’ related to the first and second stages of trance. The first of these is a circular room, illuminated only by sunlight falling through cut-outs in the metal ceiling evocative of entoptics or phosphenes. The second space is covered with a spider-web of timber lathes, creating disorientating shadows over the display panels of different phosphenes overlaid with animal images that are also cut out from metal panels. This evokes the mental overlay of known images on phosphenes during trance.
The curved walls screening the toilet entrances, experience chamber and route exits, are made from tubular steel frames anchored into gabions. The screen infill material consists of recycled oil drum lids spot welded either to butt against each other, or to overlap like fish scales where more privacy is needed, such as between the toilet cubicles.
The roof structure consists of tubular steel sections welded together in curved roof trusses. Structural work required on-site inventiveness as Maritz describes below:
All fabrication of the steel trusses and screen frames was done on site. The contractor, who was a welder by trade, built a homemade bending rig, which was used to bend the steel into shape by hand. This saved considerable cost as pre-bending in Windhoek would have been expensive and required additional transport of the made-up curves. An added benefit was that each truss could be tailor-made on site and adjusted to fit.
New roofing materials, with their high embodied energy, would have looked out of place in this environment, and also could not achieve the bi-directional curves required for the shape of the building. ‘Tiles’ for roof cladding were made by quartering recycled 200 litre oil drums and installing them in a Roman tile fashion with a row of concave ’tiles’ fixed to the purlins and closed with a row of convex ’tiles’.
Over 600 second-hand oil drums had to be sourced from all over Namibia for the cladding, causing several delays to the project schedule.
The metal was sandblasted before installation, removing paint remnants and starting the rusting process, which had a kind of ‘anodizing’ effect that helped blend the building in with the surrounding red oxide rocks.
Local unemployed men were used to gather reeds from a nearby riverbed that were used for ceilings. Wages for the workers were pre-funded by the architects who then recovered the money in the final payment. Using locally available materials, the low cost ceiling provided short term employment, and achieved exceptional insulating properties.
Trapped air in the reeds helps reduce radiation from above. Between the reeds and the drum roofing, an additional layer of silver foil also reflets the radiation from above. The building curves around an open space facing north, so that on winter mornings, the low rays of the sun can warm the interior. In summer, the sun is much higher overhead and the roof shades the seating areas. The thick stone walls soak up heat, helping to keep inside spaces cool, and the high roof shapes with openings at the top channel rising hot air to the outside.
The building interior was permeable to the outside elements as Maritz was keen to add:
It must be stressed that this is not a fully weatherproof building. It offers shelter against the sun, heat and some wind, but will be vulnerable to dust and infrequent wind-driven rain.
Terracotta clay bricks, packed and compacted on leveled sand, were used as flooring.
Most of the doors are site-made gates using drum-lids for the infill, welded to a tubular steel frame. The office and stores are provided with conventional solid timber doors for security and weatherproofing. The toilet cubicles are provided with canvas curtains that are looped back when not in use.
The nearby fountain – from which the site derives its name – was left untouched as a historical feature and to provide water for the surrounding wildlife. Water for the Center’s needs is trucked in once a week and stored in a large ground level tank. It is then pumped, by hand, to smaller higher level tanks from where its use is restricted to hand washing for the public, and showers plus drinking water for the staff. This process makes the staff acutely aware of the value and scarcity of the water.
Nine dry toilets are provided for visitors and staff. The dry compost ‘Enviro-loo’ toilets save water and avoid sewerage disposal that can cause pollution of the fragile environment.
Doing more with less is seldom achieved to the extents that it was with this small non conventional project. In a country where scarcity of resources is commonplace, the architects employed a creative frugality through the use of recycled materials, echoing the cultural, environmental, and physical contexts to produce a design response that was tied literally to the complexities and characteristics of the site. This commitment led to a self-effacing recognition that architecture, like the landscape of which it is a part, is dynamic and ever changing.
All photographs © Dennis Mc Donald and Nina Maritz.