It's set into the ground and surrounded by concrete poured around it. Seems like that might not do so good. If I wanted to cheaply find out what was in it I would drill a small hole and use a $20 endoscope. With a Home Depot drill rental you could be out $50 max vs 600-1000 for a locksmith.
A Home Depot drill is not going through the walls of any good safe.
Not to mention, just randomly drilling holes in a safe is a pretty bad idea, as it might contain a glass relocker, or any other relocker you might accidentally trigger.
Angle grinder and a shit load of disks will usually be sufficient. Takes a while, but unless they have James Bond style poison gas / acid / explosives etc embedded in the safe enclosure you will eventually make it through.
Safes are rated in amount of time it takes to destructively open, usually with power tools. Anywhere from like 20 minutes to a few hours can be expected IIRC
This is an abandoned safe in a residential installation. It doesn't have any of that shit. In the extremely small chance that the safe contains anything at all and it has a relocker mechanism, well it doesn't really matter because you had to cut through the safe to get inside in the first place.
You vastly overestimate the security of safes. It might take a while and you might kill a few drill bits in the process, but you could definitely drill through most safes, especially in home installations.
As far as relockers go, you've already resorted to destructive methods. If you find that it's worth opening after drilling, then you'll find a way in.
