Poland is a very easy country in which to do a self-drive if that interest you. Last year we flew in to Warsaw, rented a car and drove to Gdansk and stayed a few days at the gorgeous Sofitel there. During that time we drove to Struthoff Holocaust Memorial site. It was a beautiful area.
Later, we drove to Krakow as I just love that town and we drove rather than take the train since I wanted see the country and stop along the way. It was beautiful, but there were doing lots and lots of road work, so it did take a bit longer than expected. However, once we got to Krakow, everything was perfect again. Our hotel room in old town overlooked the center of town and it was the perfect room.
We did revisit the Auschwitz-Birkenau Memorial site, too. and then on to the Wawel Castle. I wanted to go again to the Wieliczka Salt Mine, but ran out of time. It is fabulous. We went the last time we were in Krakow. I could live forever going between Krakow and Venice, IT.