Monday was Pfingsten, or Pentecost, so most places were closed. We managed to do a lot of walking and see some of the sites in the heart of the city. First, we made our way through the Tiergarten, Berlin’s central park, and checked out the Victory Column located on the Great Star intersection, before heading east on 17th of June Street toward the Brandenburg Gate. A sports festival was going on with too many people around. A Christian holiday with throngs of people in a European capital next to iconic sites of Germany. Also, I had just seen “Patriot Day” on the flight, a movie about the Boston marathon terrorist attack in 2013. We couldn’t help but talk about the terrorist opportunity. We took photos at the Brandenburg Gate and continued east on Unter den Linden ultimately to Alexanderplatz. Along the way we stopped at a café on Museum Island for coffee and treat, took photos at the Marx and Engels statues, and went inside the Church of Mary that dates back to the 13th century and is known for its “dance of death” fresco. Finally, we headed south and looked at Checkpoint Charlie and the “Topography of Terror,” once the site for the headquarters of the Gestapo and SS.