Le Corbusier's vertical city in Marseille

'Shock! Horror!' These words sum up my first impression of architect Le Corbusier's famous Radiant City (Ville Radieuse) in the outskirts of Marseille.

Exhausted after a prolonged train journey, I arrived on a scorching July afternoon. The moment I stepped out of the cab, the enormous 56-metre-high fortress-like building fell on top of me. Well, it actually didn't, but it felt indeed as if I was about to be squashed by its oppressive raw-concrete Brutalism.

The moment I walked through the rows of piloti, concrete columns that prop up the structure like stilts, and entered the semi-dark lobby, I was inundated with memories of similar high-rise concrete dwellings in the Soviet Union. The only thing missing was the all-permeating cabbage-soup stench that used to dominate the doorways, the stairs and other communal spaces of Moscow apartment blocks in the 1960s and 70s.

Unlike in the latter, however, the lifts in the Radiant City were all in good order and appeared not to be used as public toilets. I got out on the 3rd floor and checked into my room ' one of Le Corbusier's renowned cellules ('cells'), modelled on a monastic cell of Galluzo, a Carthusian monastery in Tuscany visited by the architect in 1907. To reach my cell, I had to walk along a long, dimly lit corridor, lined on both sides with flats and occasional offices.

The cell was tiny and ascetic: a bunk, with a capacious storage compartment underneath, a bedside table that doubled as a cupboard, a small balcony and a minuscule walk-in shower cabin of the type you find on board overnight ferry boats. The outside toilet was to be shared with the dwellers of neighbouring units – again, a familiar feature of a Soviet communal apartment, where multiple wooden toilet seats, one for each of the sharing families, used to hang in the corridors like oversized and totally luckless horseshoes.

Notwithstanding the shared toilet, the room was surprisingly cosy, pleasantly cool and perfectly functional. Having shoved my few luggage items into the abundant wall closets and storage boxes ('as little furniture as possible' was one of the main principles of Charlotte Perriand, Le Corbusier's interior designer), I installed myself in one of the iconic LC04 steel chairs to look through my notes on Le Corbusier, the most famous and controversial 20th-century architect, and his equally famous and controversial creation – the Radiant City.

The vertical garden city

The design of the Ville Radieuse was largely inspired by the shared utilities inside the Constructivist Narkomfin building, which Le Corbusier spotted in Moscow while working on a blueprint for the House of the Soviets in the 1920s (his project was eventually rejected by Stalin). The young architect was then under a huge influence of Ebenezer Howard, the founder of the world's first Garden City (Letchworth in the UK) and his book 'Garden Cities of Tomorrow'.

If Howard's ultimate aim was to take London workers out of the late-Victorian slums and resettle them in the countryside, Le Corbusier, who hated the very concept of a conventional urban dwelling ('Let's kill the street!' was one of his favourite mottoes), aspired to build 'a garden city in the sky' to provide affordable accommodation for those who had lost their homes in the First World War. His dream was to create 'a calm and powerful architecture', which, in his view, necessitated (among other things) the use of reinforced concrete. His vertical city was supposed to be a truly 'brutalist' structure (nothing to do with 'brutality', but from the French beton bru, meaning 'raw concrete') – unappealing and even shocking (as it was initially for me) from the outside, for, to me, Brutalist architecture cared little about appearances, but practical and comfortable for the residents. The building's dimensions were to be calculated using Le Corbusier's own 'Modulor' system, based on the proportions of a human body.

The Marseille Project, commissioned by Raoul Dautry, then France's Minister of City Planning, took many years to mature and over five years to complete. It was initially pooh-poohed by the locals, who christened it 'La Maison du Fada' ('the nutter's house' in the Provencal dialect). When the building finally took shape in 1952, it was astounding: a 50,000-tonne tower block sitting on 34 pillars of bare reinforced concrete. The structure had 337 apartments of 15 different kinds, yet each of them, irrespective of the style, had a large balcony and a bay window.

Most of the Radiant City's public spaces, lifted high above the ground, were situated in fully functioning but traffic-free 'mid-air streets' on every third floor, including the main 'high street' on floor 3, with several shops (a bakery, a café, a supermarket – now closed and turned into a disco) and later a hotel. In the long and straight 'streets' (corridors) on other levels, one could find a primary school, a kindergarten, doctors' surgeries and small workshops.

The main communal area, with its Narkomfin-style shared utilities, was on the vast roof terrace. It consisted of a running track, a playground, a paddling pool and a gym. In Le Corbusier's eyes, the roof, with its 180-degree sea views, was supposed to represent the upper deck of an ocean liner, moored in the Marseille cityscape.

Not very popular in the beginning, the Radiant City eventually became one of the most desired residential properties in Marseille. Its Corbusian duplexes (two-level apartments) now attract affluent upper-middle-class professionals.

In for a walk

After a much-needed nap, I went for an evening Radiant City walk - all inside the one-building 'Machine for Living' – Le Corbusier's vision for urban dwellings.

Having left my room on the fourth floor, I walked past Dr Herve Aubin's surgery, then descended to the 3rd floor 'high street' from where muffled sounds of music could be heard. The bakery, the café and the bookshop were closed, but in a small public square near the lifts a party was in full swing: several dozen youngsters were dancing obliviously to music played by a DJ.

I took the lift to the top floor and found myself on a spacious roof terrace. Large and bright southern stars mingled with the distant lights of the off-shore Frioul Islands.

Despite the late hour, the roof was full of people. As in many southern cities, where siesta is observed during the hottest hours of the day, the residents were out for a stroll. Families paced the perimeter of the roof leisurely. Occasionally, they were overtaken by joggers running around the circular racing track. Children splashed in a paddling pool, lit up with blue lights, while their mothers practised Pilates nearby. Older residents, with coffee cups in their hands, sat on benches between a funnel-shaped ventilation shaft and a windbreak protecting the now-empty outdoor theatre stage. They sipped coffee and looked up at the stars.

I was pleased to see that despite the off-putting Brutalist exterior, the community inside the Radiant City was thriving. The 'Machine for Living' was very much alive.

I also came to realise why the building appeared so painfully familiar to me. Le Corbusier's far-reaching plans were picked up by urban developers all over the world, but were never implemented in their entirety. And whereas the Corbusian concepts of high-rise high-density buildings were put into practice almost everywhere, the architect's 'quality of space' principle (both inside and outside the tower blocks) was mostly forgotten. Hence all those drab residential 'estates' of Sheffield, Glasgow, East Berlin and East London, the 'new development suburbs' of Moscow and other Soviet cities: all poor imitations of Le Corbusier's radical, yet fully functional (as shown by the Radiant City) projects.

A frozen dream

In the morning, the corridors of the Radiant City swarmed with dog-walkers returning to their flats with their pets in tow.

I had breakfast in a superb in-house restaurant, Le Ventre de l'Architecte ('The Architect's Belly'), on the terrace overlooking the sea. The restaurant, just like the hotel, the bookshop and the estate agency specialising in 'unusual living spaces', were not part of Le Corbusier's original plan. In fact, he would have probably been unnerved by the fact that a hotel named after him was now part of the Radiant City, intended for permanent dwellers, not tourists. But tourists these days are a daily reality of the Ville Radieuse.

'Inside the building, there used to be lots of unused and abandoned spaces,' says Alban Gerardin, who bought the would-be hotel in 2003. 'We were passionate about architecture and tried to restore the rooms, corridors and terraces to the original Le Corbusier design. We scoured antique shops and flea markets in search of Charlotte Perriand's furniture pieces and placed them in the hotel rooms. The idea was to reproduce the soul of the place without too much glitz.'

I had a chance to look at a number of other cells and duplexes where Le Corbusier's esprit nouveau ('new spirit') is lovingly preserved, including the legendary apartment number 50, which used to belong to Lillete Ripert, the Radiant City's in-house nursery school teacher and Le Corbusier's friend. Yet perhaps the most convincing example of how well vintage Corbusian spaces could be adapted for modern use was, again, on the building's multi-purpose roof. In 2010, Marseille-based artist Ora Ito discovered that the old 1960s gym was up for sale. With the support of the Le Corbusier Foundation, he bought the space, restored it to its original design and, in line with the Radiant City philosophy of a 'place for all to share', opened MAMO Gallery, an arts centre to which all residents of the building have free access. When I was there, it hosted an exhibition of Dan Graham's breathtaking large-scale steel-and-glass pavilions. They fitted beautifully in the uncomplaining roof terrace, next to the children's playground.

So, what is the Radiant City? A radical architectural statement? A masterpiece of modern design and construction engineering? A village in the sky? It is all those and many more. If Schelling described architecture as 'frozen music', I would rather call the Ville Radieuse Le Corbusier's 'frozen dream' – his concrete, in both senses, vision of what modern public housing was supposed to be like.