Where should a 70 year old invest a large inheritance?

depends upon your income level. I'd contact one of the big brokers and get advice where you can share your details and goals.

If I were you I’d buy some real estate and then manage the rentals.

If you had $800,000 for example, and for example lived in my area which is a suburb outside a major city, then you could buy 2 townhouses at $230,000 each for $460,000 (paid in full in cash) and then get 3 more townhouses where you put $80,000 down on each one and then you’d be seeing like $7,000 in income a month from them ($7000 income after all expenses). You’d be set for life and the value of the rental townhomes would only continue to go up in value

I would put it in common stocks and watch them carefully.

Investing is about the big picture.  Does the 70 year old already have enough money to retire on?  What is the goal of this money?  Long term care?  Vacations?  Help grandchildren?  

This is why you talk to a financial advisor.  They will recommend where to invest (and execute on it) making you more money than they cost you.  You don't do your own heart surgery because you aren't trained.  No difference here.

Given your age, it should be invested somewhat conservatively. Many mutual fund groups offer target date mutual funds based on your age and tolerance for risk. Look for one that targets somewhere 2016 and 2020. They are targeted for people your age.

If you are not sure interview several financial advisors, preferably with a CFA designation.  There are so many personal variables, and so many things to be sure you do it'll just be worth the effort to find a trusted advisor. 

I like Fidelity.

As far as specific investments go, if you do not have enough education to do this yourself, Fidelity can help you.   If the inheritance is large enough, you may qualify for free advisor services.   If not, you can pay a very reasonable rate for services actually rendered.

DO NOT go to a full-service commissioned advisor.  They will rake 2-3% off the top of all your assets every single year.  It's a total rip-off. 

For what? long term stability? Short term gain? Depends on what you want. I'm guessing you're not saving for your old age.

At 70, his capacity for wine and women would be diminished so I suggest he invests it all in song.