Spanish sculptor Cristina Iglesias creates art from places we want to be, but can't. She tells Aidan Dunne about her exhibition at IMMA

One could say that Spanish sculptor Cristina Iglesias makes environmental installations that play in various ways with our perceptions and experience of space, natural and architectural. That's entirely true and accurate, but it makes it all sound rather dry and theoretical, and perhaps a bit forbidding.

And, in reality, her work is anything but. Actually, it is richly sensuous, intricately detailed and immediately engaging.

It is environmental also in the sense that it should be encountered at first hand. She transforms the spaces that her work occupies, but her work also creates spaces for us to be in - or, on occasion, to which we are denied entry.

With the first piece you encounter, in which a suspended latticework, illuminated from above, casts its shadow on the floor around you, she does something subtle and entirely characteristic. The latticework is composed of text. We literally walk through a space articulated by words.

That is not immediately apparent, however. You can negotiate the space without realising that words are involved at all. In fact, the first time she used a text in this way, as the constituent struts of a set of detailed latticework screens in Celosia I, viewers did not make out the words embedded in the decorative geometric pattern.

What greets you is a group of beautiful screens, finished with a bronze patina, guarding a central, inaccessible space.

"The piece is partly about the possibility of deciphering the text, and it can be done, but with a great deal of difficulty," as Iglesias judiciously puts it. Deciphered and reassembled, the text turns out to be from Joris-Karl Huysmans's Against Nature - "One of my favourite books". The point of Huysmans, for her, is that it is a description of a fantasy space that exists only in words and imagination, but one that could exist in fact. It is one of several comparable texts she has used in this way.

"When I was planning Celosia I, I was looking for passages of text describing places that didn't exist, because I had this very definite idea that I wanted to create a structure that is made by words, I mean literally A on top of C and so on, constructed from words." Her invented, inaccessible space is indeed constituted by words, though we may not be immediately aware of it. There is an exotic quality to the interlinked bronze panels. Except that another layer of subterfuge is involved here. The screens are actually made from wood and finished to resemble bronze.

The evocation of an imaginary space that we cannot enter is at the heart of the work, literally and metaphorically. "I was thinking of spaces and places where we desire to be, but cannot, for whatever reason. That state of being somewhere but longing to be elsewhere." In subsequent Celosias, we do have access to at least some of the internal spaces that she creates. But it is not quite as simple as that. The pieces are arranged so that one space always leads on to another, literally or in terms of the kind of longing that she describes. Spaces in her work are often echoed or turn back on themselves. They're rarely simple or straightforward.

"I always seem to be building walls," she says of herself. In one series of pieces she literally does create concrete walls in big, rough slabs. But, in each case, the wall begins to curve outwards, as though peeling away, to reveal a decorative tapestry of a pastoral scene on the reverse.

"There's a reference to an exterior landscape which is at the same time artificial." The effect is quite magical.

For her Vegetation Rooms, there are walls with a difference. She created cast bas-reliefs based on compositions of dense interlocking masses of plants, stalks, leaves and flowers, and, in one extraordinary case, octopus tentacles mingles with twigs. "I always try to make motifs that could extend indefinitely, to infinity." That is to say, there is no beginning or end to the expanse of the vegetative tangle. "And I try to suggest or imply indefinite depth." This allows her to create extremely flexible environmental spaces.

You might, for example, enter a space flanked by vegetative "walls" to find that they quickly converge and bar your progress. But psychologically, you feel that the vegetative thicket proliferates and fills the room around you. The effect can vary from being luxuriantly sensual to slightly threatening, depending on the nature of the imagery and the space.

Her photographic polyptychs, some of which line a long corridor at IMMA, play with our sense of scale. They depict a series of monumental architectonic spaces which we quickly realise must be, in reality, very small, because they are greatly enlarged studies of what might be described as a cardboard city. Elsewhere she refers to the way that, in examining something close-up, "You can discover a whole other world in the detail". It seems fair to say that, in classical structuralist fashion, she works in terms of a series of oppositions: inside and outside, natural and synthetic, real and imaginary, access and exclusion, word and image, heavy and light, solid and transparent, big and small. But she continually disorientates our reading of these oppositions, creating expressly ambiguous, even conceptually impossible imaginary spaces, forms and masses.

The same applies to her use of materials, the way wood is convincingly disguised as bronze, for example. Or the fact that her bas-reliefs similarly employ metallic or stone powders with light resin to suggest greater materiality. And there are the concrete slabs which are made with the use of a special lightweight cement. She clearly likes things not to be quite as they seem, but she also likes to let that awareness filter through to us. "I use many materials that look heavier than they are," as she puts it. "I like to provoke that sensation of weight, but I also like people to realise that, no, it's actually much lighter."

You do realise that, and it makes the experience of encountering her work all the stranger, and all the more rewarding. Few artists have the potential to change your way of looking at the world, but Iglesias is one of them.

Cristina Iglesias is at the Irish Museum of Modern Art, Royal Hospital, Kilmainham until October 5th (01-6129900)