Don't forget the tangible part of your investments. For instance, you could buy or lease a slice of farm land and plant a couple of walnut trees. After a couple of years, you can harvest walnuts, which is a nice change for your usual routines. After around 50 years, the wood is grown enough to be sold on the market. Walnut is one of the most expensive woods. If you think long-term, Walnut or something alike is certainly worth becoming a milestone of your lifetime portfolio.
If you don't have that possibility, you may get into contact with a farmer and offer him an investment in return for naturals. For instance, you finance him a tractor or harvesting machine and in return you get a life time's worth of meat, milk, cheese, eggs, fruits or vegetables.