The only thing worse than boring everyone with the pictures of your vacation is droning on and on about all the wise conclusions you drew from 72 hours in another city. It takes years to understand a place like the natives, and that goes for Richfield as well as Rome.

On the other hand, snap judgments have their place. Sometimes you conclude that a city is messy and unfriendly because it is. Sometimes you love a city’s color and charm because it’s colorful and charming. It’s unwise to conclude that your brief impressions are the whole story. If someone came to Minneapolis in January they’d say it’s cold and monochromatic, and they’d be correct — but that would only be part of the truth.

Now that I’ve dispensed with the caveats, here’s why Minneapolis needs a little more Paris and a lot more London, based on my summer vacation.

Paris is beautiful, because it was commanded to be beautiful. Napoleon III ordered up a pretty city, and he got one.

In the middle of the 19th century, Paris was a ragged warren of cramped streets and tenements, ridden with poverty and disease. Just as in the urban renewal movement in the postwar years in America, Napoleon decided to mow it down and build anew.

He hired Georges-Eugene Haussmann, a fellow who’d studied law and music before settling down into a civil service career. Napoleon put a map of Paris on the wall and drew thick blue lines where the new boulevards should go. Haussmann made it happen, and gave the new streets a distinctive look that relied on a lack of distinction. The same colored stone. The same style of ornamentation, block after block. Everything was the same height.

What might have been: A 1917 plan for Minneapolis included this rendering of a Parisian-like green area and buildings near City Hall.

You don’t need to understand much French to grasp what Napoleon told Haussmann to do: aérer, unifier, et embellir. Give it air, bring it together, and embellish it.

Oh, and parks. Big ones. Oh, and two monumental train stations. And an Opera House. It cost a fortune and took 20 years, but in the end there was the Paris you know from pictures or trips, a unified work of art whose ideas spread across Europe, and then to America.

The City Beautiful movement, inspired by the shining classicism of the 1893 World’s Fair in Chicago, sought to bring the diagonal boulevards and uniform heights to the chaotic ad hoc American cities. A plan was even drawn up for Minneapolis that made us look just like Paris, with City Hall taking the place of the Arc de ’triomphe.

City Beautiful is a beautiful idea, a unified aesthetic. But that means it doesn’t deal well with contrasting styles. Modern Parisian skyscrapers, with the exception of one dull stalk, have been kept at the edge of town, like an angry mob not allowed into the walled garden.

The sameness of the city makes for harmonious views; our apartment, in a 1912 building designed to the Haussmann ideals, was indistinguishable from everything up and down the block. When you sat on the tiny balcony and looked out at the world, it had a unity that spoke of a coherent culture, rules and ideals. Alas, Victor Hugo was right: He lamented that it was difficult to tell what a building was for. Theater? Cafe? House? Shop?

The new look was a shock to some who appreciated the old Paris, and Haussmann’s critics accused him of destroying history. “We weep with our eyes full of tears for the old Paris, the Paris of Voltaire, of Desmoulins, the Paris of 1830 and 1848,” said one critic, “when we see the grand and intolerable new buildings, the costly confusion, the triumphant vulgarity, the awful materialism, that we are going to pass on to our descendants.”

Of course, now everyone loves it — which is a signal to some urban planners that the critics will be mocked by history, and that the grand schemes will be validated by the steady march of progress.

We should be grateful that the planners who tried to remake Minneapolis in the 1950s and ’60s didn’t have the power and purse of Napoleon: Washington Avenue would be lined with indistinguishable glass-and-steel structures, an inert canyon.

The buildings that replaced the Gateway were erected over decades, and thus we have architectural diversity that makes for a much more interesting street. Which brings us to the lessons of London.

If Paris is the result of the wishes of an Emperor, London is the visual equivalent of the House of Commons and the House of Lords — a mishmash of styles, opinions and ideas good and bad.

It has some grand streets and vistas, mostly designed by John Nash. But it is a city of individuals, not masses. It’s a place of surprising intimacy, not theatrical gestures. The government centers of Paris are either gated, like the old National Assembly building, or prefaced by acres of manicured parks, like the Louvre.

In London there’s a green space across from the Parliament, big enough to let the area breathe, small enough to feel like a backyard, not a grass moat. The new skyscrapers are a mixed bag, and they don’t cohere into a skyline like the towers of New York, but they punctuate the city and give you something interesting to behold if you choose to look up.

That’s a big if. London, like Paris, is old and hence low-slung, but the building stock is infinitely more varied. Our hotel was a renovated 19th-century structure across the street from a gloomy ’80s office block. A beautiful glass tower rose a block away. Around the corner was a street of three-story buildings — pubs, restaurants, a bookstore. The scale goes from old and small to new and grand in the space of a few steps, and while some lament the new projects, the overall effect is dynamism mixed with tradition.

Finally, I decided that Paris is a pretty portrait. London is a novel.

If we could go back in time and ask the city planners to pick one thing from European models, what would it be? Some might like a Paris-style monumental boulevard. Many would beg for a subway system.

No, Minneapolis can’t justify an underground rail system the way Paris or London can, but wouldn’t it be great if they’d built one in 1895, and kept going?

The first leg might even be paid off by now.