Two trips work without a car. Auschwitz-Birkenau Memorial lies about 70 km to the west; admission to its grounds is free, but entry cards must be reserved online at visit.auschwitz.org, so plan that one a long way ahead.
The guided Tourist Route runs 3.5 km through the old workings, with more than 800 steps; allow 2 to 3 hours for it.
Tip: Tickets are priced by season: PLN 103 from January to April and October to December, PLN 119 in May, June and September, PLN 125 in July and August. The route runs 9 am to 5 pm from January to March and in November and December, and 8 am to 6 pm from April to June and in September and October. Book online for the slot you want.