Apple - How to disable frequently visited items and favorites under the address bar in Safari 8?
Go to Safari Preferences → Search and disable Show Favourites.
You can actually remove "Frequently Visited" without disabling "Favorites" now by right clicking the background of the "New Tab" page. I did this in Safari 10, not sure if this works in Safari 9.
- Settings -> General -> New tabs open with: Favorites
- Open a new tab
- Right click on the background
- Uncheck "Show Frequently Visited Sites"
This setting in the "new tab" page is now also reflected in the URL bar.