We went to Krakow for a 3 night break, but ended up staying for 8 nights due to the Icelandic ash cloud, as a result we experienced the city during a State funeral as well as in the rain & sunshine!
Even in the rain the city is beautiful, the architecture is stunning & the cobbled streets add to the experience. The main square is a big attraction with the merchants houses lining its perimeter. Beware, the Cloth Hall is being refurbished at the moment so it not fully open & is not at its best with the scaffolding surrounding parts of it. Many of the souvenir stalls are outside in green cabins, but you can find very nice presents there.
St Mary's Basilica is worth a visit. You must buy a photo permit at the ticket office, they strictly enforce this rule ,so be aware! If you hear taped music being played go to the alter & see the carved fresco being unveiled from behind its ornate screen, quite a theatrical spectacle! St Barbara's next door is worth seeing too, very ornate.
The castle grounds gives lovely views of the river. You can see the dragon statue breathing fire at regular intervals from the walls too. THe castle courtyard is lovely; in the rain the dragon drain pipes pour water from their mouths, great to see from the safety of an umbrella! We did the tour of the State rooms. They are very starkly furnished, not very exciting, but passes time on a wet day.
We used Krakowdirect to take us the Salt Mines & Auschwitz. Their drivers speak excellent English & were very helpful & punctual. There may be cheaper options, but we'd recommend their services.
The Salt mines are a unique experience. You walk down 300+ stairs, its reminiscent of going into the deepest Swedish sauna you can imagine due to all wood clad walls! The tour guide we had spoke excellent English & talked about the various salt sculptures without over burdening you. Each cavern was more spectacular than the last & culminated in the cathedral like cavern with many religious scenes carved in the walls. You go to a cafe underground, but there is another ,bigger one once the tour ends with plenty of tables. Well worth a trip!
Auschwitz should be regarded as a visit to pay homage to the victims of tyranny, not just another tick in a travelogue box. We went in the rain which added to the experience. You do not need a guide if you have some historical knowledge or indeed younger teens with you too much detail causes distress& detracts from them getting the message;the piles of shoes,cooking utensils & other personal belongings speak volumes about the camp . We bought a guide book (4zl) & followed the well marked route. Do go to Bircheau. Only there can you get an inkling of the scale of the horror, row after row of chimney stacks, the remains of the accomodation blocks that housed the victims before they were sent to the gas chambers.A sobering experience, but worth making.
On a lighter note, the Poles are very friendly & helpful, many speak excellent English, but have a go at their language, it is appreciated; we only said "Jan koo ya" , Thank you, but you get an even warmer reception! Try Polish food, it's very tasty & certainly different from English fare. Coffee shops abound, cappuccinos & lattes were excellent where ever we had them.
There a plenty of tourist information offices with lots of information in English.
If you can't fly into John Paul II try Katowice airport. It's 1.5 hours away from Krakow, we managed to fly out from there with Wizz Air when nothing was happening with Easyjet at John Paul!
Krakow is a wonderful city with plenty to do, I'd recommend it despite our enforced stay!