Sunset's original posting can be found at viewtopic.php?f=6&t=4712
My guess (and that's all this is) is that this is a souvenir bell to commemorate a visit to an area known for its prison where executions were done. It does not look like an old bell and is quite crudely cast so I would not think this is a "high end" bell. The inside of the bell does not show a lot of wear. But, then, this is not a bell that would be used every night to summon the servants to the dinner table!
Having said that, it certainly is a unique bell and makes for a great conversation piece! Enjoy it!