I opted for Liberty Lincoln Safe years ago, built into closet which would require walls to be torn down to remove it. The safe will stay with the house
Not a guarantee against theft but another layer of protection. I also have the safelert service which allows me to check on temperature, humidity, door open/close status etc. It has a very sensitive "shake" feature that when triggered texts me. If I lay a hand on the safe I receive a text within ~30 seconds. If wifi mysteriously goes down I receive a similar notice. I can also set custom triggers on temperature and humidity which is helpful if you are, for example, in a high humidity environment. This feature can remind you to turn on the dehumidifier (safe has its own dry rod dehumidifier, one of several accessories you can consider). Tornado and fire are more likely than theft in Iowa; the Liberty safe provides some protection from all (heavy, quite a few layers of fire board, ball bearing steel hardplate, 14 bolt, etc.).
http://www.libertysafe.com/safe-linc...html?tab=specs
http://www.libertysafe.com/accessory...-17-pg-85.html