Most recognisable girl in the room: Daniel Gabriel Rosetti’s 1866 Regina Cordium, on show in the JAG’s centenary exhibition.

As you walk into the majestic space of the Edwin Lutyens-wing of the Johannesburg Art Gallery – through the entrance that faces the railway lines – you are confronted with two utterly superb Dumile Feni drawings. They tower over you as they reach, in their characteristic brutal charcoal linework toward the space’s high ceiling, effectively taking your breath away.

And, by the time you have meandered through the rest of the exhibition spaces constituting the celebration of the building’s centenary, you kind of wish the Dumiles had indeed taken your breath away, and that that was all you’d seen.

Not that the quality of the work on display is bad; rather the all-pervading sense of neglect hangs like a pall over the gallery, which shows its most precious gems in earnest honour of the building’s milestone. But further to that, a lack of guidance or literature and the absence of any gallery staff – it was a Sunday early in the year that I visited – leaves the space feeling ominously mausoleum-like.

The entrance you use finds you slap-bang in the middle of one of the curated exhibitions, but there’s nothing to advise you of this fact; you walk hither and yon until you encounter a different exhibiting context. And still, nary an indication that this is the second of the suite of six exhibitions curated for the building’s milestone. This lack of pamphlets or information or help of any description leaves you focused more on where one exhibition ends and the next begins, than on the work itself.

There is, admittedly, a large text on each of the exhibitions’ introductory walls, but you have to find it to appreciate it. And just over a month after the grand opening, a lot of the letraset-like letters stuck onto the walls are beginning to peel off.

While the exhibitions individually and collectively speak of much focused work and thought by the curators, and are clearly projects at great pains to showcase the JAG’s wonders, there are unforgivable horrors in how the museum’s maintenance is neglected. Yes: the roof has been attended to and hopefully over the last couple of rainy days has proved watertight, but there are so many areas in this beautiful space that suffer the indignity of rot.

Maybe two thirds of this museum should have been shut to the public, for the centenary and the remaining third be given the careful attention to detail on lights, walls, floor and ambience it deserves.

Having said that, the exhibitions’ curators must be lauded for bringing out old treasures and precious secrets from the JAG’s holdings – some you may know well – they may be your favourite favourites that resonate with times past in this gallery’s auspicious history, including the Picasso harlequin drawing, the Whistler etchings, the Siopis Melancholia painting that launched her popularity in the 1980s and the 1866 Daniel Gabriel Rosetti Regina Cordium, arguably the collection’s most recognised paintings.

Others you may not have seen before, such as a remarkable piece by Gerard Marx near the gallery’s entrance that reflects in a three-dimensional mosaic on an aerial view of Johannesburg, and a glorious Adolf Jentsch landscape and some incredibly fine John Koenakeefe Mohls. And yet others may trigger your memory of exhibitions that you’ve loved. There are some stunning works by Gladys Mgudlandlu, Jackson Hlungwanes to make you gasp and fierce and haunting works by Valerie Desmore.

In the space containing the display of African traditional works – from the collection of the Oppenheimer family, the display of objects might be encased in glass cabinets, but this doesn’t blur their unequivocal magnificence. From decorative vessels to headrests, walking sticks to figures, these mainly wooden pieces honours its promise of being among the best in the world.

The exhibition of Pre-Raphaelites curated by Sheree Lissoos is delicious, if you can pull your eyes from the flawed teal walls on which they’re hung and look through the ill-lit glimmer. It’s a crying shame: the works are jewel-like, reflecting a mid-19th century work ethic, touching on values opposed by radical artists such as the Impressionists. In these conjoined rooms, curated with a sense of the works’ emotional and historical value, you understand why the paintings are scorned as mawkish, but also to appreciate how all-consumingly beautiful they are.

Still armed with nothing, by way of literature or explanation, your ramble may lead you to the exhibition of works on paper, where you will see some Daumiers, a Hockney and some Kentridges to knock your socks off, or you may reach the exhibition of video art in the JAG’s most modern wing which was built in the 1980s.

In this latter exhibition, alongside wall signage, there is an open door, through which you see a stash of broken gallery furniture: if this is part of performance art, it is not marked as such. There’s also a very large unlabelled abstract painting on the wall alongside the men’s lavatory: was this too big to have been moved? Why is it unlabelled?  It is somewhere between that point and the Mohau Modisakeng video work that you cannot see because it is labelled as such but not switched on or working, that you experience the desperate need to get out of JAG altogether, before you lose all hope altogether.

The JAG’s centenary is an important series of exhibitions. Not only because of the work showcased, but also because in its upkeep and staffing it reveals the kind of benign neglect that you see in the Pretoria Art Museum, discussed here. At the JAG, however, there’s an urgent focus on the part of the curators to hold onto what we have by way of culture. But it’s a gesture that so obviously lacks support from the civic bodies under whose responsibility it falls, it is quite simply a disgrace.

• The JAG’s centenary on until March 1 comprises: Curator Sheree Lissoos’s exhibition of Pre-Raphaelite work; Encore, an ensemble of the JAG’s popular favourites; Moments in a Metropolis, curated by Tara Weber, is an exhibition of work on paper; Pastoral Pieces: Significant African Objects is curated by Karel Nel and Philippa van Straaten; South African Art 1940-1975, is curated by Antoinette Murdoch; and The Digital Underground, a glance at electronic and digital art, is curated by Musha Neluheni. Call: 011-725-3130