I honestly believe that the only truly safe investment is in land, because then at least if the worst happens you can always just live off the food you grow there, everything else is relative to the time you're in.
You cannot take your land and flee if you have to. In the event that you must leave the area you are in then you will have to leave your wealth, and it will not be a good time to sell.
Also, around here I would have to pay a yearly tax the the government to have my land and I would not own the mineral rights and if they wanted to build a highway through it I could not stop them. In Canada you don't own land, you pay for it then you rent it from the government.