Gold/Silver, is a part of a diversified portfolio. It's a good inflation hedge. It also provides no yield or monthly return such as real estate.
Don't buy gold from a broker. they will charge a 30% commission and will deeply cut into your returns. I made that mistake my first go around. Luckily gold went up a lot in that time.
It's extremely liquid.
An important thing to keep in mind is that gold coins don't have value just for their weight in gold (of course that would not be true in the oft-lambasted apocalypse scenario). Gold coins also have a "numismatic" or collector's value.
For instance, if you buy a 2016 Gold Buffalow coin just issues, it's worth about the spot price of gold.
If you buy a rare 1 oz. 1906 gold, no motto St. Gaudin dollar coin which was only produced for 6 months in 1906, it's worth a lot more than that ounce of metal. This numismatic value can offset the loss of value incurred as bullion and metals are pretty volatile.
I personally hold a few gold coins and a bunch of silver for the unlikely apocolypse scenario. In that case, having silver to have smaller coins to trade would be good, then some gold for large purchases so as not have to carry around as much silver.
Also, I don't plan on divulging where I keep my gold, but it is not in a safe deposit box or held by an outside company. The majority of thieves won't go hunting for your safe that's bolted to the concrete slab or floor joists behind the water heater in your basement and will just go for the easy stuff like ipads and phones and get the hell out of dodge.