Gold and high precious diamonds would be a great alternative if you want to. Its worth wont go down but up in such collapse simultaneously in the bank and cryptocurrency. But to hide it on the safe is a different story, it needs more than security but also luck. So before doing so, make any plans in advance about those area of putting those or you might be on hide and seek with criminal elements around.
I agree with Gold, as in gold jewelries. I remember I have like 50 grams of gold before and its like x5 by today's price. So I think gold and other precious jewels such as diamond is a good investment besides crypto's because the price could multiple many times and can grow exponentially overcome. But just remember to keep them as well in a safe place just like your bitcoin private keys. So that it will not be stolen by someone. And the good thing about gold jewelries is that its easy to pawn, so if you need an immediate cash, you can just go to a pawnshop and immediately exchange it for cash if you need money in an emergency or something.