This one map of Berlin shows all you need to know about Europe's refugee divide

Huge gains for an anti-immigrant party in East Berlin reflect the East-West divide in Europe as a whole.

Yesterday, German Chancellor Angela Merkel waited nervously in her unassuming Berlin residence while the voters in Germany's capital city determined her fate.

The vote taking place outside her door technically had nothing to do with her. It was a local election for the Berlin Parliament (landtag), not the national one (bundestag). Berlin and two other German cities (Hamburg and Bremen) are, for historical reasons, also federal states.

But the result would have a direct effect on Merkel's chancellorship because it came hot on the heels of her centre-right CDU party's humiliating defeat in her home state of Mecklenburg-Pomerania. The CDU came in third, behind the centre-left SPD and, alarmingly, the new nationalist party Alternative for Germany (AfD).

Merkel's far-right home state

The German chancellor has suffered an embarrassing electoral defeat as the dark cloud of nationalism spreads over Europe. But predictions of her political demise are premature.

Last month, I took a trip with some friends to the Northwest German island of Rügen in the Baltic Sea. It's a beautiful holiday island full of white chalk cliffs and rolling green hills. But when we were there, it was also full of sights of a more disconcerting variety - political ads for the far-right and racist messages splattered in graffiti. 

As we left Berlin on the train and travelled north through Mecklenburg-Pomerania, signs for the far-right Alternative for Germany (AfD) and the extreme-right (neo-Nazi) National Democratic Party (NPD) became more and more frequent. They were all over the island, and were an especially frequent site in the island's departure city, Stralsund. On the posters for the main centrist German parties, Angela Merkel's center-right CDU and the center-left SPD (who are currently governing the country in a coalition), was written a chillingly familiar word in graffiti: volksverräter (traitor to the nation).

The only ads not splattered with grafitti were those for the AfD and NPD, some of which called Germany's new arrivals "rapefugees".

This is Chancellor Merkel's home turf - the constituency which she represents in the German parliament. And like parts of neighbouring Poland, it is not a friendly place for people of color.

Gleisdreieck: the new Berlin wall

The old border between East and West may be imperceptible these days, but Berlin still feels like two different cities.

This week, after I had finished moving into my new apartment in the Neukolln neighbourhood of Berlin, I went to the annual re:publica conference nearby. It's an event focused on the politics of the internet - a subject close to German hearts. 

It is held at The Station, an extraordinary event facility housed in a former postbahnhof - a train station for mail. Today it sits under a dizzying intersection of several different train lines at Gleisdreieck Station - where U2, U1 and DB long-distance tracks converge. It has a beautiful outdoor area that faces Gleisdreieck Park. 

But this spot wasn't always so lovely. For decades this area was a barren weed-filled wasteland under and along the railroad tracks, separating the West Berlin neighbourhoods of Schoneberg and Kreuzberg.

German unity, but not reunification

Tomorrow is the 'Day of German Unity', marking 25 years since East and West Germany were merged. But don't call it 'reunification day'.

The area around Brandenburg Gate, once home to the 'no mans land' between the two layers of the Berlin Wall, is tonight being decked out for a massive celebration. Tomorrow, 3 October, is the annual celebration of 'German Unity Day'. This year's holiday is no ordinary one. It is marking 25 years since German reunification.

But don't make the mistake of calling it 'Reunification Day'. I called it by this name with a German friend today. I was swiftly deutsched, and told that despite the fact that it is held on the anniversary of the day the East German government was merged into the West, the proper name is 'unity day'.

I was only repeating the term I have read in English-speaking media, as there have been several reports this week about the 25th anniversary. But there are two important reasons why this is not called Reunification Day: it corresponds to an older holiday name, and because pre-war Germany has not been entirely reunited.

A royal palace reborn

The Humboldt Forum will emulate the old Berlin City Palace, but not copy it.

Since I've been here in Berlin I've ridden my bike across Museuminsel many times on my journeys between East and West. I've been meaning to check out the construction site for the Humboldt Forum, where they are building a replica of the old royal palace that was torn down by the East Germans.