Getting rid of "slide" adds?

MBP Late 2011 R15" Retina.
Running Sierra 10.12.5 and Safari 10.1.1

I'm not sure if that's what they're called but every few minutes at the top right hand side of the screen an alert slides in from "9to5Mac".
No idea where this is coming from and I don't want it. I've been on their website and there is nowhere where it gives me the option to get rid of them.
Any suggestions please?

Those are Web Notifications..in this case from the 9to5Mac website..so if you were to visit that website through Chrome, on the URL bar click click on the (i) next to the URL and you'll see a bunch of options, one of them will be Notifications, set that to Block to avoid this in the future..

Ah, thanks for the hint! I use Safari but they also have a "Notification" area where sure enough 9to5Mac was set to "allow". This has now been set to "Deny" so hopefully end of problem!

Excellent, yes that's how to stop this..