If you want to put your money someplace and get more money later, there are 6 ways I can think of to do this.
1. Stocks
2. Bonds
3. Real Estate (Houses, rental, raw land)
4. Commodities (Precious metals)
5. Loans (Lend money to others)
6. Collectables (Art, furniture)
For true diversification, I think some money should be allocated to all of these vehicles.
There is another investment one can make that would indirectly make money. And that is to invest in oneself, which would primarily be through education. And I think everyone should continually be doing this.