The best way to understand the quirkily designed Dominican priory near Lyons is to spend a night there, says Emma Cullinan.

I spent one night of my holiday this year in a concrete cell - just a little bit wider than my outstretched arms and just taller than my upstretched fingers. The en suite facilities comprised a single basin with a tap that proved difficult to turn off once it got going. There were no curtains on the window - instead a broken curtain rail lay on the floor.

When I first saw the room I got the jitters about sleeping in the small stark space - with its single bed topped with a plain brown linen cover - betwixt a simple timber wardrobe and desk.

Six hours after checking in I couldn't wait to bed down in my cell - I had better acquainted myself with the overall building and got to grips with where the architect was coming from. I had a fantastic night's sleep although other members of my party did admit to still being spooked by the space.

When you first see La Tourette - a priory for Dominican friars, designed by Swiss-born architect Le Corbusier - it does indeed look stark and foreboding. It is a vast concrete structure that sits atop a hill (perfect for pilgrims on foot who like to work hard) just outside Lyons in France. The first structure you reach, when arriving on foot or by car, is a much more locale-friendly set of old farm buildings with red-tiled roofs that house a reception, chapel, kitchen, plus accommodation. The priory sits above these to one side and offers a large concrete wall to uplookers.

But there are already signs that a master has been at work and the foreboding façade contains human elements. This is, for instance, expressed in the balconies that are facing you at this point which are not of a uniform size. Then, as you walk up towards the building, you better appreciate the curved shape of the crypt attached to one side of the building and the funnel-like protrusions from its roof. These are reminiscent of the water collector beside Le Corbusier's chapel in Ronchamp, France, which the architect had recently completed.

The building was commissioned by the same art-loving Father Marie-Alaine Couturier, who had befriended Picasso and commissioned artists such as Matisse and Rouault to decorate churches. "It would of course be ideal if Christian art could be revived by men who are both geniuses and saints. However, if such men do not exist, we believe that it would be much safer to commission geniuses with no religion," he wrote in his publication Art Sacré.

Le Corbusier was reluctant to design churches as he said he wanted to design buildings that people would live in and because this building was to be used to house friars, he was persuaded.

The brief was for accommodation for 100 friars to live and work in. The key difference between friars (or in French frère, i.e., brother) and monks is that monks would traditionally work within a closed community whereas the remit of friars was to go out and teach the surrounding community, while their own accommodation was closed to visitors.

The austerity required by the Dominicans is amply catered for here in a building that provides the aforementioned cement cells for friars and a fortress-like exterior, alluding to fortified churches built in the middle ages.

But, as with much of Corbusier's work, the building offers much more than first appears with delightful structures and quirky proportions contained within. This is why La Tourette is worth spending the night in: you can really get to grips with the building, walking under it and through it. The deal is €50 a night, including evening meal, lunch and breakfast.

You share those meals - a cheeseboard starter; fish pie main course and fruit for pudding in our case and the best croissants I've ever tasted for breakfast (we left before lunch) with earnest educated types and architects from all over the world. Some stay for a long time: there was a woman in for three months completing a thesis, propelled along by the silent cell that has a balcony onto wooded parkland.

This isn't a hotel for all-comers through, you need to book in advance and it is worth giving your design and/or Catholic credentials. You can see why, the place still houses 15 friars and the silence and ethos is to be respected: although the echoey acoustics in the building have proved a real problem.

Of course, La Tourette wasn't designed as a hotel but the sheer pressure from architects the world over, climbing the hill to see the Corbusien wonder, which was completed in 1960, led them to open it up for those who wished to worship, whether that be of a religious deity or a design god (or both).

By this stage, Vatican II had occurred (in 1962) so an opening up was easier and it is still possible to see where the building caters for pre-Vatican II, for instance, in the crypt where each friar took individual Mass. It also enabled the Dominicans to spread their teaching into the community - as was their wont - even if the community now came to them.

You enter the priory through a free-standing portico that is designed - like many elements in the building - along Modular-man principles. Le Corbusier used this model of a man - based on the Golden section - to give humans a sense of harmony with the building. The cells and certain floor slabs are as high and as long as a tallish man with an outstretched arm (2.26m). The entrance, while being of human proportions, symbolises the leaving of the human world to the spiritual one of the building.

Other human elements include a trapezoid window that was meant to be square but the wooden formwork collapsed. When the builders offered to put it right, Corb told them to leave it because it showed the human input into the building, mistakes and all.

Once through the portico, the building becomes quite barmy in places and that is probably why people grow to love it. While the cells and corridors may be austere, and the surface finishes and meeting of elements pretty rough, there are remarkable elements, especially in the places where people pray. The oratory is a tall, slightly off-centre pyramid and the crypt is shaped like an ear to symbolise the friars listening to the world outside. Within, the crypt has the funnel-like roof lights: one white (life), one black (death) and one red (no one is quite sure why). Corb just used primary colours and shades from nature, and the palette in this building comprises green, red, blue and yellow. In the refectory a window panel is in primary coloured squares in reference to the artist Mondrian.

The plumbing pipes are painted either blue, for cold water, and red, for hot - again a way of linking people with the functioning of the building. These pipes are said to have influenced the design of the Pompidou Centre in Paris.

The sacristy roof has jutting objects on top of it, now known as "machine guns".

THE church has coloured slit windows and the armrests between seats alternate between concave and convex, to keep church goers thinking. There are also extremely delicate, unexposed light fittings, at foot level on the stairs; again keeping people on their toes. Le Corbusier felt that it was important that people negotiate fragile areas.

The effect is to set you on a treasure hunt as you walk through the building waiting to discover what astonishing design decisions have been made. For instance, the black spot painted on a floor below a candle so that the wax drops would disappear. Those touches are delightful.

There is a slight sense of anything goes here, and when asked what the random pile of cement near reception was, Corb said it was his poo.

Father Couturier trusted Le Corbusier and there is a sense of the architects really going to town: providing a surrounding frame and then filling it with unearthly delights. This was one of Corb's last buildings and he was very busy at the time, working in India on his buildings in Chandigarh. But he was at a stage of his career where he had learnt many things and was confident about showing what he could do. Also, he was not prepared to build just for building's sake: when the build estimate came in too high (as it always does) and cutbacks had to be made, Le Corbusier wasn't inclined to compromise the design too much (although the original steel frame gave way to shuttered concrete walls, and the building was lowered by one storey). "At 68 years old I do not have to prove that I can make inexpensive architecture," he wrote at the time.

He also concentrated on the important parts: when asked why the stairs were so steep he said that he wasn't concerned with designing these - other parts of the building were more crucial.

The front of the building is currently clad in scaffolding as the structure undergoes its first restoration in its 50-year life.

Because he was so busy, others in Corb's team had considerable design input, notably Iannis Xenakis, who had studied engineering in Athens, before applying to work with Le Corbusier.

His CV also includes composing and when he came to design the wall of the chapter, he followed both Modular principles and musical compositions. He worked out a way of mathematically reproducing a piece of music and then applying this to window spacing.

This is all part of the module built, Modern building with Modular proportions and musical modulations.

The result is a wall that dances, as does much of the building, a point made at a dance and poetry show that happened the evening we were there in which we followed the leotard-clad dancers and serious orator through the building. "La lumiere dansante," he said.

As well as helping us to better understand the building's vibrancy they also displayed the effect it has on those who work there. They were passionate about the building - despite its slight madness - and it's easy to see why. It is a complex character that takes some getting to know and by spending a night here - rather than an hour or two - you grow to love it.

To book a room: Centre Culturel Couvent de La Tourette, Eveux, 69591 L'Arbresle, Lyons, France; tel: 0033 474 26 7970; culture@couventlatourette.com