Belgium

The postcard had a Belgian stamp on it, and a message: "I think this is self-explanatory."

Is it?

Fortunately or unfortunately, additional explanation was at hand, in the caption in the lower left-hand corner, in French and some other languages. It turns out that the artist is Anu Tuominen, and the work is Fleur de Sel, completed in 2002–2004. The medium, if you must know, is saltshakers and travail de crochet.

From the intertubes, I see that the artist was born in Finland in 1961, and that she doesn't always work in saltshakers and crochet. Sometimes she uses a cheese slicer and knitting, sometimes mittens and socks, sometimes clothespins. In closing today, we have a work by Anu Tuominen done all in red and blue pencils.

It would be understandable error if, assuming you had nothing to go on but this one pair of pictures, you came to the conclusion that not much of anything really happened in Europe during the twentieth century.

The top picture shows the marketplace in Ghent, Belgium, in 1900; the lower photo was taken from the same vantage point in 2010. Of course everything in this part of town--the Korenmarkt--had already survived very nearly intact from about the 11th century until photography was invented and the streetscape could be snapped at the start of the 20th century. Presumably, nothing much was happening back then in that neck of the woods.

Except for Paris, Ghent was the largest and wealthiest city in Europe until the late Middle Ages. In the United States, old parts of cities tend to survive intact if the city experiences prolonged poverty, during which time redevelopment is economically unattractive. I don't know if the same dynamic accounts for neighborhoods that last a thousand years in Flanders and the rest of Europe.