Often placed in a tower, and so sometimes an inhabitant of last week's campanile. The one I grew up closest to was in a cathedral tower, though, plus the local zoo had one. The instrument was developed in the Low Countries, but the name was adopted in 1775 from French, from of Old French quarregnon, from Medieval Latin quaterniōn-, set of four, from which many presume they were originally four bells. Modern instruments are instead typically four octaves, not four bells, though they range from two to six octaves (the largest are 77 bells/notes). Wikipedia has the usual more information.
As we passed the cathedral, I could hear someone practicing Bach on the carillon.