We stayed in Krakow for 2 days only, of which one was dedicated to a Wieliczka Salt Mine visit. Taking this tour on the second day was the best thing to do, since in about 4 hours, it allowed us to get an overview of the city, and learn about its history and origin, by visiting the main sites. We were also lucky to have an excellent local guide, who told us all sorts of exciting stories about Krakow.
The tour's pace is very easy, and the route is very well organized, with a lunch break halfway through the tour, in the neighborhood across the Vistula River, which allows you to enjoy the view. The second part of the tour explores exactly this less-known part of the city, which we would've missed visiting otherwise.
Big thumbs up for the complete organization.