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.
Gold and diamond are the safest investments as their prices are very constant in nature and there is always a possibility to get profit from it but the ratio of profit is not so much high if we compare it with other investments like in business, buying houses, commercial shops or private companies etc.