Frankfurt (Oder), Germany

Frankfurt (Oder) sits on the Oder river at the German-Polish border, an hour east of Berlin by regional train and twinned by treaty with Słubice on the Polish side since 1991. Founded in 1253 as a Hanseatic League merchant town and a key crossing on the Berlin-Poznań trade road, the city is dominated today by three things: the European University Viadrina (originally 1506, dissolved 1811, refounded 1991 as a German-Polish-East European cooperation university with a partner Collegium Polonicum on the Słubice side), the brick-Gothic Marienkirche with its restored medieval stained-glass windows (returned from Saint Petersburg's Hermitage in 2002 after 60 years), and the Kleist-Museum in the birthplace of dramatist Heinrich von Kleist (1777-1811). The Stadtbrücke (City Bridge) crossing into Słubice is the easiest border walk in Europe — pedestrians cross freely under the Schengen agreement, and the bilingual signage and shared bus services blur the line that the Oder once formed. The city's defining institution is the Viadrina: 6,000 students from 80+ countries, three faculties (Law, Business, Cultural Studies), and the only campus in Europe deliberately positioned as a German-Polish-Eastern European bridge — the academic geography mirrors the physical one. Beyond Viadrina and the cathedral, Frankfurt (Oder) is a quiet, walkable town with the Konzerthalle Carl Philipp Emanuel Bach (named for Bach's son, who studied here at the original university), the Brandenburgisches Landesmuseum für moderne Kunst, the Lennépark and Kleistpark with mature plane trees, and the Helenesee lake five kilometres south for summer swimming. The wider Märkisch-Oderland district stretches north into the Märkische Schweiz nature park, the rolling lake-and-forest belt that Theodor Fontane immortalised in 'Wanderungen durch die Mark Brandenburg'. Train: RE1 to Berlin Hauptbahnhof in roughly 75 minutes, every hour; the Berlin-Warsaw EuroCity passes through twice daily.