In short
Berlin is a city that was cut in two for twenty-eight years, and that history remains legible in its fabric: the eastern and western districts share neither architecture, nor street width, nor kerbstones.
Mitte is the historic and institutional centre. Kreuzberg and Neukölln are the cosmopolitan, alternative districts. Prenzlauer Berg, in the east, has become family-oriented and well-off. Friedrichshain keeps the nightlife.
Arriving and getting around
BER airport is to the south-east, linked to the centre by regional train in half an hour.
The network is excellent: S-Bahn, U-Bahn, trams — above all in the east, where they were never removed — and buses. Berlin is very spread out: the distances surprise, and cycling is a real answer, the city being flat.
What it really costs
Berlin remains one of the cheapest capitals in western Europe, but the gap is closing fast: rents have risen sharply and the subject is politically charged.
Cash payment remains common, including in restaurants and bars that do not take cards. Carrying notes avoids awkward situations.
When to come
May–September. Winter is long, grey and cold, with very short days.
Shops are closed on Sunday, apart from stations and a few exemptions: shopping on Saturday is a habit to acquire.
What nobody tells you
Checkpoint Charlie is today a reconstruction surrounded by shops, with actors in uniform. The place that actually explains the Wall is the Bernauer Strasse memorial: a preserved section with its full apparatus — outer wall, patrol strip, inner wall — and a documentation centre. It is free.
The East Side Gallery is a stretch of wall painted by artists in 1990, on the eastern face; it is a work made after the fall, not period graffiti.
Tempelhofer Feld is a former airport turned public park: you walk and cycle on the runways. Berliners rejected building on it by referendum in 2014.
A line of double cobblestones marks the wall's course through the streets of the centre. You cross it without seeing it unless you are looking.