Berlin’s intense history challenges visitors to explore the complex mix of sites and memorials in the sprawling capital of Germany.   My recent visit was haunting and invigorating. Modern Berlin is an intoxicating mix of graffiti-adorned alleys, glitzy restored palaces, and solemn symbols of its turbulent past. I was awed by the majesty of the Brandenburg Gate and moved to tears at the Memorial to the Murdered Jews of Europe.   As I explored this fascinating city, I admired Berlin’s ongoing efforts to refurbish and...