If you want to keep something safe, the best place you could put it is in the bank at Gringotts. Gringotts is the bank of Witches, Wizards and magical creatures that inhabit the world of JK Rowlings Harry Potter. Harry himself visits the famous bank with Hagrid in the first book, the Philosophers Stone. Here he finds that he is actually very rich, despite being told he was very poor by his Uncle and Aunty.
The bank is run by Goblins. These magical beings are known for their officious manner and protective nature. They are not the most attractive looking creatures either. They take their job very seriously, and any attempt to rob the bank is met with swift curses and the full magical force. You can be sure that the Goblins will have taken note of the work of the famous muggle Locksmiths Exeter based company https://www.guardiansecuritysw.co.uk/locksmiths-exeter/.
It’s best not to ask what other security measures they have. In the last book, “the Deathly Hallows”, it’s revealed that they have a Dragon captive in the bank’s depths. It’s not a very good idea to go anywhere near one of these huge beasts at the best of times, let alone one that’s been chained up. When it does escape, with Harry’s help, it wreaks havoc. A fair bit of rebuilding is needed afterwards.