quote:

e may need to contact his cc company and let them know he's travelling with the card(s) out of the country.

Yes, he should definitely do this!
Berlin has changed enormously since I was there last in 1990. There are a lot of Muslim migrants and extreme Leftists; not sure where they hang out, maybe around the railroad stations and central Berlin near the Zoo. But there are some really worthwhile things to see (Museuminsel with the Pergamon Museum); Dahlem is a beautiful suburb; the Wannsee out in the west is a great place to spend a sunny day. It’s easy to get around on the U-Bahn and S-Bahn.

I loved visiting Poland in 1990, and although I haven’t been in Poznan, loved visiting Krakow and Warsaw. Auschwitz is a must-see. Poles are very, very pro-American; Germans maybe not so much. But a lot has changed in Germany since all the migrants from Syria and Afghanistan came in.

I’ve never been to Berlin, but I’ve been to Poznan a few times, as the company my wife works for has a substantial office there.

The food there is very good, but my favorite pierogi restaurant closed down, I’ve been told. The town square is worth a walk around. There are WWI and WWII cemeteries, with sections for ALL the combatant countries. There are a couple of military museums, one for vehicles and one for weapons. There is also a general museum, and I believe the prototype concentration camp is nearby, but I never made it there.

A lot of the people speak English, but not as many as in Germany. I got some dry cleaning done by myself and the young lady working there using translation apps.

I never felt uncomfortable walking the streets of Poznan, but it has been a few years since I was there. Much safer than some parts of Germany.

As others have said, pay with credit cards or Apple Pay as much as possible, with some Zlotys for places that don’t accept credit cards or Apple Pay.

Keep any valuables in one of those inside the pants passport carrier. NOTHING in back pockets especially. Be instantly on guard if someone bumps into you.