Mapungubwe Interpretation Centre by Peter Rich Architects, Mapungubwe National Park, South Africa

The confluence of the Shashe and mighty Limpopo rivers mark the area where the borders of South Africa, Botswana and Zimbabwe meet. Here, vast tracks of veld with rifts of beautiful native trees such the fever tree and the remarkable baobab alternate with valleys, flat-topped hills, jagged horizontal ledges and groups of rounded stony hillocks.

This is the landscape of the Mapungubwe National Park, classified as a World Heritage Site because of the important archaeological discoveries made here. Graves containing artefacts from the 9th to 12th centuries indicate that the site was occupied by traders with Egypt, Persia, India, Malaysia and China.

In 2005 South African National Parks held a competition for the design of an Interpretation Centre on a plot set away from the main archaeological site. Johannesburg-based Peter Rich won. Rich has a boundless passion for architecture in general and for indigenous African architecture in particular - its cultural significance, and how buildings interrelate and integrate with their environment (AR March 1995). His design was also declared the Building of the Year at last year’s World Architecture Festival (AR December 2009).

The project not only provides unusual and imaginative exhibition spaces for disseminating the intricate history of successive civilisations who have occupied this area from the 9th century until the present, but it also raises awareness of the vulnerability of the local ecology and the importance of its preservation. All this comes underpinned by a strong social dimension. Unemployed local people were taught and inspired to use the surrounding earth and rocks to make building materials and employ these in construction.

Visible from its entrance gate, the Mapungubwe Centre is approached through a valley from where the outcrop of new buildings merges naturally into the southern slope of a rocky plateau. From here, there is a view to a hill about 1km away, where the original archaeological site was discovered and excavated. The clever analysis of the site and the way it is structured to accommodate the programme becomes more apparent as you move from the entrance in the valley to the plateau 14m above.

From here, the whole complex is revealed and linked visually to the archaeological site on the hill beyond. As you experience the sequence of changing directions, the orientation and variety of structures, from lightly covered walkways to vaulted spaces, all punctuated by open courtyards landscaped with rocks, plants and pools, you can only marvel at the ingenious organisation of a complex and historically potent site.

A series of equilateral triangles structures the landscape and the way the buildings address it.

The triangles are designed around an axis linking the centre’s entrance and the archaeological excavations. This axis traverses the site, running parallel with the hilltop ridge and rivulet below. It is not obviously articulated, but nonetheless provides a subconscious appreciation of the ordered way in which the buildings are grouped and the informal flow of outside spaces and planned landscape elements between them.

Rich was aware of the significance of the triangle in local Venda culture; a common arrangement is three dwellings placed in an equilateral triangle and linked with low walls. He had also seen isolated triangles carved into stones at the nearby archaeological site.

Arriving at the parking area (tactfully obscured by a hillside spur), you move past an outdoor introductory exhibition to cross the open veld to a group of shade-providing trees with views of the south elevation. A sloping bridge brings you to the reception cairn, which is punctured by an oculus so the sun’s light bathes the interior. A free-standing vault generously spans the space between the ablution and restaurant facilities.

From the reception area a darkened passage curves around the cairn to an inclined, elevated walkway with a slatted timber floor and mesh screen balustrade. Shaded by tall trees on either side, you reach a heavy, stone-clad sloping buttress marking the threshold to the crypt-like exhibition areas. In these spaces vaulted tiled soffits exhibit the faces of people who have been part of the historic continuum of Mapungubwe.

Peter Rich carries his sketchbook with him wherever he goes, so it is no surprise that he has cultivated an acute awareness of the light and shade, shapes and patterns of the world around him. With its alternating veld, valleys, stony ledges and rounded stony hills, Mapungubwe is a fascinating landscape.

The introduction of synergic buildings into this terrain prompted Rich to consider the use of timbrel vaults - ancient structures originating in the Mediterranean region 600 years ago and still in use today by the Catalans. Shaped by natural structural forces, large vaulted spans can be achieved with minimal roof thickness. Local materials were used to make the brick vaults and because of the simplicity of the construction, unskilled labour could be employed. This had the advantage of being both economical and providing work for local people.

In collaboration with two structural engineers (John Ochsendorf of MIT and Michael Ramage of Cambridge) Rich devised a timbrel vaulting system consisting of three vault types.

He describes these as ‘a rectangular or square vault taking the natural distribution of horizontal compression forces via the hyperbolic parabola through buttresses to the ground’, ‘a circular timbrel dome’ and ‘a shallow pitched vault spanning between horizontal structural supports’.

The vaults resemble a system of caves, which is culturally significant. Caves were regarded here not only as places of refuge and shelter but were also used ritually, in rainmaking ceremonies. Large areas cut out of the vaults admit a soft, almost sacred half-light to the exhibition areas inside. These openings are protected from glare by polycarbonate sheeting and eucalyptus stalks, and from baboons with iron grilles based on the pattern of kanniedood plants growing in the courtyards below.

External terraces are shaded by horizontal slats to create areas reminiscent of the traditional African gathering space, or kgotla. The shaded areas and covered walkways bind together the landscaped spaces between the buildings which are planted with the indigenous species of the surrounding veld, so nature seems to flow through the structures.

Passing through the sequence of different spaces, vaguely aware of the triangular ordering system as you ascend through the building, you finally arrive at the generous vaulted exhibition area at the building’s summit. Curving in two directions, the lofty, undulating vaults bear lightly on the side walls. Coloured light falls through the glass panels on the south wall and the famous Golden Rhino, one of Mapungubwe’s most precious treasures, shines in its own impressive display cabinet.

A sense of serenity prevails, unifying artefacts, architecture and nature. Peter Rich’s orchestration of space and light resonantly connects the building with site and history, evoking wonder at the memory of so many civilisations that walked the earth before we did.