Auschwitz-Birkenau; we visited both.
St. Maximillian Kolbe was killed in Block 11 of Auschwitz I (the fourth photo from the top). We prayed at his hunger cell (the fifth photo from the top). Everything has been kept original, including the paint job.
Visiting this killing center is chilling. It reminds one of the abortion mills of today. Silent holocaust. Millions slaughtered in the name of whatever, because it is/was legal to do so. Any opposition is ruthlessly opposed by government and popular culture.
Auschwitz is an easy day trip from Krakow. It is a haunting place that is a must see for visitors to Poland.
Amidst all of the horror of this episode in history, the priestly vocation of St. John Paul II was forged, in the shadow of this and the Divine Mercy convent of St. Faustina in Krakow. I wish everyone could see these places.
FYI: we are putting together a Spiritual Highlights of Poland FSSP Pilgrimage in 2018. Stay tuned for details.