Sometimes, a peculiar historic circumstance turns a city into an outsized point of convergence.

In his memoirs, the German artist Hans Richter recalls his arrival to Zürich in September of 1916.  The city was island of peace smack in the middle of WWI Europe.  Almost two years earlier, as they were about to be mobilized, Richter and two of his Berlin friends had made an unlikely date to meet in neutral Zürich, at the Café de la Terrasse.  Entering the café, he not only found his two friends, but also sitting at a table nearby, Tristan Tzara, Marcel and Georges Janco, the trio of Romanians among the Dada group.  Dada was centered at the Cabaret Voltaire, only a five-minute walk.  There Richter met the other early figures of avant-garde movement: Hugo Ball, Emmy Hennings (whom Richter already knew from the Café des Western back home,) Richard Huelsenbeck and Hans Arp.  Across the street lived Vladimir Lenin, barely more than a year before the Soviet Revolution.  Just around the corner was the studio of the pioneering choreographer and dance theorist Rudolf von Laban.  Sophie Tauber and Mary Wigman were among the young dancers in Laban's studio.  James Joyce was often sitting at a table of the Cafe Odeón, near the Terrasse.  Perhaps having a conversation with Ezra Pound...

By the way, Tom Stoppard's 1974 play "Travesties" wonderfully captures this ebullient Zurich of WWI.