A safe anchoring device for anchoring a safe to a floor. In addition to anchoring the safe, the safe anchoring device simultaneously provides a watertight and airtight seal for the interior of the safe. A tunnel connects the interior housing to the exterior housing. Insulation is between the interior housing and the exterior housing. A removable top cover covers the tunnel on the inside of the safe at the interior housing. When the anchoring device is used to anchor the safe to the floor, a removable threaded locking bolt extends through the tunnel and is threaded onto a threaded tube section of a bottom cover while the bottom cover is securely attached to the floor. In a preferred embodiment, when the safe is anchored to the floor the watertight and airtight seal is provided by a gasket under the top cover and an O-ring under the bolt head of the threaded locking bolt. When the safe is not anchored to the floor, the threaded locking bolt is removed and the bottom cover covers the tunnel at the exterior housing. In a preferred embodiment, when the safe is not anchored to the floor the watertight and airtight seal is provided by gaskets under the top cover and the bottom cover.