Mars. Have Elon take you. Once you're there, I'll send the coordinates.
I keep mine in a safe at a friends company (they are staffed 24/7). I would not use a safe deposit box because they have been raided over the years (google it). Your best bet is a small fireproof safe that is well hidden at your house or at a family members. I sort of do the same thing for my offline coins...I can not access them without driving to multiple locations.
If someone is worried about their deposit box being raided, it's unwise to store valuable stuff at home