This orange Zastava 101 gets beeped at a lot as it trundles along the boulevards of New Belgrade.

A sign of affection for a classic car, of the kind the original Volkswagen Beetle enjoys? Not quite.

"It's because I'm slow," says Natalija Ugljevarevic, the 23-year-old at the wheel of a car better known as the Yugo.

Dating back to 1971, the model is more than twice her age. And while the Tito-era people's car has a surprisingly roomy interior and boot, it's not exactly a design icon.

But Natalija is running a "YugoTour". The car and the sights of New Belgrade are definitely enjoying a moment, as the concrete blocks bask in international recognition for their contribution to urban design.

Towards a Concrete Utopia, an exhibition of socialist Yugoslav architecture, has just finished a six-month run at New York's Museum of Modern Art.

And increasing interest in the brutalist school of architecture is making New Belgrade a mecca for connoisseurs of raw concrete.

YugoTour's guided trips have come along at just the right time to take advantage of a demand to know more about the dozens of "bloks" which are still home to 250,000 people.

"I studied architecture and saw the buildings in one of my lectures, so I decided to come and visit," says Perry Li, who is from China but went to university in Britain. He's now taking in the highlights of New Belgrade through the windows of the Zastava.

"Many of the buildings are on a very large scale and they look powerful to me. I also want to know more about the history behind them."

Marshal Josip Broz Tito built an authoritarian, socialist Yugoslavia after World War Two. The federation broke up in conflict in the 1990s.

Natalija wrestles the car into a parking space opposite the Western City Gate.

Next to the motorway leading from Zagreb and the airport, its linked twin towers were supposed to inspire awe in new arrivals to then-Yugoslavia's capital.

It was the crowning glory of Tito-era architecture when it was completed in 1980. But now it is in a sorry state.

A tower formerly occupied by the state-owned Genex company is empty. The revolving restaurant above it stopped turning decades ago.

The residential tower is still home to scores of people - and the views across the confluence of the Danube and Sava rivers are spectacular. But the forecourt is littered with weeds, graffiti and broken tiles.

It is a microcosm of the challenge facing New Belgrade. Just as it is surfing a wave of positive international attention, its concrete creations are crumbling.

"What we're faced with is the bad maintenance of that quality space, which is a really sad thing," says Danica Jovovic Prodanovic, co-founder of Belgrade International Architecture Week.

"The quality of New Belgrade's urban design and social housing was much better than nowadays. It's very important for us to recognise the value of that heritage - it hasn't been valued enough, and we need to preserve it."

In the Yugo, Natalija shows off one of the best examples: Blok 23's village-within-a-city, where the residential buildings surround green space, a sports centre, kindergarten and school - and belie New Belgrade's reputation as a concrete jungle.

"This is a place for living, relaxation, schools - then you have the green area. You're protected here, your kid is safe here," she says.

Other stops on the tour include the spectacular Sava Centar, a conference and performance venue which seems to have taken its interior design cues from science fiction, mixed with classicist and modernist styles.

And for full immersion in Tito-era design, visitors can stay at Yugodom.

This "stay-over museum" is actually a flat in Belgrade's old town, gleefully decorated in period-correct shades of green and orange. Guests can interact with the 1970s and 1980s accoutrements - from tangerine telephones made by Iskra to wood-panelled Elektroindustrija televisions.

Owner Mario Milekovic says it is an opportunity to reconsider the qualities of Yugoslav design.

"Before coming, people might look at our website and think the furniture here is from Denmark. Then they realise it was made in Yugoslavia - and that we had mid-century modern design."

It is now almost 30 years since the violent disintegration of Yugoslavia.

At the time, it seemed like the ideals that drove the country might disappear for good - not just Pan-Slavism, but the utopian vision for how increasing numbers of people could live in urban areas.

But perhaps the success of businesses like YugoTour and Yugodom suggest that its design can offer some inspiration - if not answers - for those looking to solve conundrums posed by modern city life.