Krakow
Totally easy to get to from the airport - train is about £3, but if it's a family then a Bolt ( Uber ) is cheap as chips. Download the Bolt app before you go and you get around 5 half price trips and you won't wait more then 2 mins at the airport
The whole of Krakow is totally walkable
So much to see and do and cheap as chips if you eat and drink away from the Square, although that's not dear when comparing to UK prices
We went October and had beautiful weather, I had put my winter coat on to travel in as it was minus three here that morning, by 11am, I was trying to stuff it in my carry on bag as I was melting. Went back in March - and froze .
The salt mines are a must for all the family. . A lot of people take in Auschwitz-Birkenau, I couldn't , but we walked out to the Krakow camp which was the setting for Schindlers List ( its demolished now - but its a huge memorial park and still very moving and interesting )
The Schindler factory is a great tour, nowt to do with Schindler, its the history of Krakow during the war years, very moving, very interesting
The castle , we did pay for entry , but it's a museum, we left after one paid tour. The grounds and are worth the visit
Krakow Zoo is supposed to be very good. A lot of older teens and young adults enjoy the shooting ranges
Food is amazing , and plenty of choices for veggies
Public transport is cheap, and clean. You buy your day ticket and just before your bus/tram/train arrives, you put it in the yellow machine to date and time stamp it . You do that the once and then just hop on and hop off at will . The trams are good
Dont just cross where you like, use the crossings, you can and will be fined on the spot
So far we have been twice, and we will return, as there is just so much to see and do , and the food is seriously delicious . We went to Prague last October and whilst we enjoyed our time, and again good food and even better beer, we preferred Krakow