Reddit reviews A Preppers Guide To Underground Bunkers: Choosing The Best Bunker And Preparing It For A Disaster(Urban Collapse, Prepper Survival Guide, Preppers Pantry)

Any particular reason you want to avoid equities and bonds over a "very long investment timeline", unless you think society is going to irreversibly collapse between now and retirement?

Avoiding those two assets means you want to essentially avoid capitalism - as they are the bedrock of capital allocation (and how it gets around the world).

If you believe that to be the case, I would recommend:

• Sepp Holzer's Permaculture: A Practical Guide to Small-Scale, Integrative Farming and Gardening
  
  
• A Preppers Guide To Underground Bunkers: Choosing The Best Bunker And Preparing It For A Disaster(Urban Collapse, Prepper Survival Guide, Preppers Pantry)
  
  
• Stocking up on cigarettes and hard liquor - in economic collapse situations, both of those commodities are extremely useful in bartering for services, such as escape
  
  
• Having a variety of hard currencies in various denominations (EUR/USD, possibly JPY/CNY but less required), gemstones (rubies and diamonds, generally cut) sewn into various clothes
  
  
• Make friends with fishermen or move to the coast, so in the event of an emergency, you can GTFO of this rock, easily and quietly
  
  Or perhaps I have misinterpreted your post and you feel equities and bonds are not risky enough for your taste, and you want uncorrelated returns to broader developed equity and credit markets.
  
  In which case:
  
  
• Hedge funds in their purest form are meant to "hedge" against the market returns - you probably want to look for absolute return strategies
  
  
• Casino table games - blackjack if you play perfectly, and somehow manage to count cards might, might see you have a positive EV, but you'll probably get kicked out before then. Roulette, my usual, has a quite negative EV, not recommended.
  
  
• Unfortunately I think commodities are generally somewhat correlated with equities and bonds, so they are out (yes, including gold and crypto). That leans more towards exotic assets such as: wine, classic cars, stamps, art - but they are correlated to the fortunes of ultra high net worth individuals and well, money laundering, so that may have a correlation to world equity markets.
  
  If, in reality, it is between those two extremes, then I would simply recommend you read Tim Hale's Smarter Investing, as well as some other sidebar reading material.