Money market funds seem safe, but don't always keep up with inflation -- so, you lose that way also
At age 70 you probably don't want to be much in stocks. The market may go down, and you may not have enough time for it to recover. So, are people long-lived in your family?
There is no such thing as set it and forget it investing. Buy and hold kinda blew up in 2002 and 2008. You have to follow the business news, and read and ponder an investment book every quarter.