Sunday morning on Bernauer Strasse and the Berlin Wall memorial is thronged with people making an essential stop of any visit to the city. Once home to the world’s most notorious dividing-line the site retains the power to deliver an overwhelming sense of place.

For many, the experience represents that simple tick of the box that says it’s Berlin, so we’ll get a selfie at the Wall. Yet amongst all that, and the endless procession of graffiti artists working their paint along its remains above the giant flea market nearby, there are vivid indications of the pain that the wall still represents. Some are plainly visiting in pilgrimage, with silent tears, their fingers tracing a name here or detail there along the memorial.

Within the living memory of most of us, people died attempting the simple act of crossing east to west. Researchers estimate at least 138 people died from gunfire at the hands of East German guards between 1961 and 1989. They included a one-year-old child and an 80-year-old woman. Photos of the dead at the official memorial include children of six, 10 and 11. Such barbarism went on in a city notorious already as the lair of one of the world’s most evil regimes before 1945. Even after the Nazis, it is hard to imagine the mentality behind machine-gunning an infant.

Berlin is a magical city today, the re-born capital of unified Germany, and a tourist destination for stag parties and city breaks. An expatriate British population is growing in hipster-trendy areas like Kreuzberg and Neukolln, often creative people attracted by the city’s comparatively cheap living and easy accessibility. The Spanish are here in numbers, attracted by the availability of work. If we measured economic progress by the number of cranes in the sky then Berlin is indeed bustling, if not quite booming.

It is remarkable Berlin can experience such rebirth after a century of horror, dictatorship, catastrophic bombing, humiliating defeat and political division. It has done so whilst facing up to its history, not least by ensuring that while much of the physical 140km of Wall is gone, its footprint is commemorated and marked – literally – in the ground.

The grinding logic of mutually assured destruction kept Europe’s differences in check for decades after 1945. Known officially as the “Anti-Fascist Protective Wall”, but in fact thrown up to stem a “brain drain” that had seen more than three million people flee to the West, the Wall served its dismal purpose, albeit one that represented a failure to manage peace in harmony.

Twenty seven years since its collapse, Europe faces great economic and political tests. Refugees wait at its borders, fleeing war and poverty. To the east, a newly-combative Russia bristles at what it sees as Western interference in some of its former client states, and is suspected of seeking to disrupt the European Union itself.

These are testing times. The prospect of a Brexit vote in June’s UK referendum makes continental Europeans more nervous. The European membership debate has spilled from Tory salons into the pubs and TV studios of ordinary Britain. Viewed from the Wall, this referendum seems supercilious and petty. Europeans want a partner, not a semi-detached fairweather friend.