I will be in Krakow this week-end. I have heard that it is possible to see Auschwitz and and the salt mines on the same day.What are my options for getting from one of these sites to the other? Thanks.

We had a rental car so it was no problem for us, but do get an early start. I do remember that the hotel desk had information on excursions offered by tour companies. They weren't cheap though.

It possible by public transport, but you would need to take a minivan to the mines to arrive as soon as they open. Do the tour, but don't linger. Take bus or minivan back to Krakow, and take train to Auschwitz (train station is Oswiecim or something like that).

If you have rental car or hire taxi for the day, it should be easy.

The tour of salt mine takes about 2 hours +, not counting the time getting a ticket or the time standing in a line waiting for one's appointed time (unless your Polish is good). And, if you self drive, be sure to get excellent directions, as it's not easy to find with merely good directions. We probably spent 4 hours from the time we left the pension (which was 6-8 miles away) until we drove out of the mine parking lot.
At Auschwitz we probably spent 3 hours+ , thinking that as out-of-the-way it was, we ought to see every aspect of it, rather than a cursory, 1 hour on-site visit. We're glad we did. So my contribution to your question would be to plan them for separate days if possible.

Auschwitz is not complete without seeing Birkenau (approx 10 minute drive from Auschwitz). You'll be emotionally drained upon return to Krakow. As per the salt mine, please allow at least 3 hours. It's a completely different mindset.

that will be like beauty and the beast in the same day.

i was exhausted after the salt mines,(then lunch) and we were even driven by a friend there. how many hundred steps down to bottom is it??

and the people behind you just keep moving.. so no dawdling.

if you are claustrophic, the elevator ride back up will really be something.

I agree with tomboy. They are best seen of different days if you can.

See not only on different days but spend more than 3 hours at Auschwitz and Birkneau to really seem the horror of WW2.
You will probably want to have a quiet dinner and retire early!

I agree with everyone who strngly advises you to do them on separate days. One is physically exhausting, some 800 or so stairs down the mine and Auschwitz will and should do you in emotionally. Its just not an easy visit. Both are so worth it, you can do the salt mine and the krakow sq and cloth market on the same day. Auschwitz and a quiet nice dinner afterward on another day.