You can get fire resistant and waterproofed safes which can be bolted to the floor. You can also get floor safes which are built into a concrete floor, hidden from intruders and practically impossible for a burglar to remove.
The thing to keep in mind is that any safe can be cracked and they are as much a means of delaying a skilled thief :ninja: as a preventative for an unskilled burglar.
I would be quite happy with any reasonably built safe I could bolt down in a discreet location.