Trains from Krakow. Be careful of the ticket lady at the train station, she's notoriously unfriendly.
The Chapel of Skulls, like similar ones around Europe, is a small room with walls and ceiling entirely covered with human bones.
At the Galos Salt Caves, you can sit in a room made of sea salt and lit with colored lights, and relax to the piped-in sounds of New Age music and birdsongs. It's supposed to be quite good for your skin.
In the central park is a mineral spring where for one zloty you can sit and drink unlimited amounts of four kinds of mineral water from a beautiful wrought-iron and glass spout.