St. Adalbert's (Wojciech) Church is one of the oldest (and smallest!) in Kraków, built in the 11th century. It includes a variety of styles, from Romanesque to Gothic, Renaissance to Baroque. They have concerts here every evening at 7; we didn't go to the concert but did find a time to go in when there weren't too many worshippers there. This is the back of the church, which I quite liked; for a view of the front, on Market Square, see http://www.pbase.com/helenpb/image/143558563