Contrary to appearances, these people aren't here to see a popular rock band or the premiere of some groundbreaking play. They're here to listen to a lecture on architecture.

The 52-year-old architecture historian, on this particular day decked out in a dapper navy-blue suit and vest, has become something of a phenomenon among Praguers who take an interest in the history of their town. Alongside his regular lecture series at Kaštan and at Dům u Černé Matky Boží, Lukeš's guided weekend walks through Prague's forgotten quarters have also become a hit, sometimes attracting a crowd of as many as 100 architecture fans.

"People are clearly becoming more and more interested in architecture, which is excellent and very important," says Lukeš, who has worked at Prague Castle's heritage department for more than 15 years. Aside from lecturing, writing about architecture, organizing exhibitions and saving historical buildings from demolition, Lukeš also teaches at New York University in Prague. In the past, he's taught at Prague's Academy of Arts, Architecture and Design and is the former dean of the Faculty of Architecture in Liberec.

"Under communism, many architects here were building stupid panel houses or buildings with no artistic value, such as the Congress Center," he says. "Slowly, architecture here is regaining the prestige it once had."

Sitting in his Prague Castle office, with a window overlooking the pointy roofs and spires of Malá Strana, Lukeš highlights some of the difficulties Prague faces as a historical city in a rapidly evolving contemporary society. Several times throughout the interview, he gets up to marvel at the view from his window, illuminated, on this particular afternoon, by pale winter light.

"When it comes to how Prague should evolve, there are two extreme views here: one is to conserve Prague in its original state," he says.

"I consider this option to be very dangerous because if you make Prague into an open-air museum, it will become an El Dorado for tourists but all semblance of normal life will disappear. We can't let the city become a carnival attraction."

At the same time, though, new projects need to be selected with great care, Lukeš says.

The early 1990s brought an anything-goes approach to architecture in Prague, and many projects created at the time were too brash and disrespectful of their surroundings.

"There was too much of an effort to meet all the demands of the investors," he says. "There was a lack of experience here."

He singles out the glass Myslbek building on Na Příkopě as one such project.

The building, he says, is average but not "an outright tragedy."

He has far harsher criticism on Vinohrady's pink Hotel Don Giovanni, which he cites as the worst recently constructed building in Prague. "It's absolute kitsch," he scoffs.

Still, Lukeš maintains that urban planners and preservationists shouldn't be afraid to let the city evolve. "In the early 1990s, some people were saying that we shouldn't let too many international architects design new buildings in Prague because it would ruin the city's character," he says. "This, of course, is nonsense.

"Just remember all the debates over the Dancing House. The public was very polarized, but today it's become one of Prague's modern landmarks."

Forty years of communism halted Prague's natural evolution, Lukeš says, and today it takes Praguers time to accept contemporary architecture.

"Czechs are conservative — under communism, [there were] very few daring projects, mostly panel high rises," he says. "That's why projects like the Dancing House encounter so much opposition here at first."

Which is sad, Lukeš says, given that Prague used to be one of the most important centers of modern architecture in the world, up until the arrival of communism in 1948.

Where different styles coexist

Although the hub of culture and commerce for centuries, Prague was never a town as rich as Rome or Paris. Lukeš says this was paradoxically a very lucky thing. Old buildings were rarely torn down to make room for new ones. To save on construction costs, existing buildings were often incorporated into new ones.

"Prague is a metropolis unlike any other in that all the different styles here coexist — sometimes in the same building," he says.

"I try and explain this to my American students and they find it quite puzzling," he says. "It's not uncommon to have a building with a Romanesque basement and foundations, a passage with Gothic arches and a Baroque facade. The resulting combinations are often very bizarre."

The wing of Prague Castle that houses Lukeš's department is the perfect example of such a combination.

"Right now we're sitting in the new Royal Palace," he says. "There used to be Renaissance buildings here, and in this wing Rudolf II had his kitchen. The facade of the building was later rebuilt in a late Baroque style, but the interior walls remained the same. The castle continued to evolve.

"Maria Theresa tried to rebuild Prague Castle into a chateau. She succeeded in this on the south-facing side that overlooks the city, but, on the north side, she never finished, so you will still see old watchtowers, and battlements and passageways — all those remnants of a medieval castle, which is, of course, quite curious. She also didn't have enough money to fill the moat on the north side."

Tremendous potential

But, while a lack of finances helped preserve Prague's idiosyncratic melange of styles, insufficient funds also meant many areas of the city were left to deteriorate, particularly during the cash-strapped decades under the communist regime.

The city now needs to invest into revitalizing its neglected areas, especially former industrial quarters like Smíchov, Karlín and Holešovice, according to Lukeš. The industrial quarters have lots of disused factory spaces available to be converted for other purposes — housing or office spaces.

Such efforts have been especially successful in Karlín, Lukeš says.

"These quarters are also very quickly becoming part of the city's historical center," he says. "There is tremendous potential there. The quality of life in these quarters can be even better than in Prague's downtown. The prices are bound to go up dramatically there. While the historical center, which is so full of tourists and has a dearth of parking spaces, is losing some of its appeal."

Of course, few major revitalization projects are without controversy. Take the Palladium shopping center on náměstí Republiky. While City Hall expects that the huge complex will help revive the shopping district around Revoluční street, a number of preservationists bemoan that the project — which was incorporated into a complex of historical buildings that used to house the Imperial Army barracks from Bohemia's days as part of the Austro-Hungarian Empire — will bring in too much traffic and destroy the character of the buildings.

Lukeš disagrees.

"Some of the more conservative urbanists, many of whom I greatly respect, think there should be a park in the area, which is completely absurd. Who would invest billions of crowns into reconstructing the barracks without expecting to get a return for that investment?" he asks.

"I think that the Palladium project on naměstí Republiky will revive the area and make it more attractive for other investors," he says. "It will expand the city center, which, at the moment, is bursting at the seams. It will expand toward Žižkov. I think it's also great that the investor retained the most valuable elements of the Army barracks. I don't mind that the barracks are being used commercially. The only thing I have a problem with is the scale."

Challenges for urbanists

The biggest challenge for urbanists these days, according to Lukeš, is the revitalization of the so-called sídliště — massive stretches of panel high-rises built on the outskirts of Prague and other larger cities under the communist regime.

"Something must be done as soon as possible," he says. "It's becoming quite urgent."

According to Lukeš, the social problems of rundown housing tracts have been underestimated for a long time in the Czech Republic, largely because the social makeup of a sídliště population was quite different than in other European countries.

While in Western Europe, the large housing tracts were built as social projects for the city's poor, here most of the population lived in high-rises and you would have university professors living next door to a poet, doctor, a plumber or a tram driver. Even President Václav Klaus once lived in a panel high-rise, when he worked as an economist before entering high politics.

When society started restructuring itself, the first people to leave were the successful ones, entrepreneurs, doctors and so on.

"This trend will continue, so the people who remain behind will be the socially weak ones who can't afford to move out," he says. "This could create massive social problems, and these places could completely deteriorate and turn into ghettos."

What to do?

According to Lukeš, one of the methods to prevent this would be to build other, higher-quality housing between the high-rises to bring in wealthier people.

"They do this in Germany, where they also replace the deteriorated parts, like old doors and railings, with new, higher-quality ones — often more luxurious than really necessary, but it serves to raise the standard," he says.

It's also important, Lukeš says, to revive these buildings at the street level — getting some shops there, building new additions — basically make these housing complexes more dense.