In Microsoft Windows I'm used to being able to type Win+R, then
C:\Temp, and that will open up the file explorer in the directory specified. Is there a similar way to navigate to a folder in Ubuntu (16.04)?
Alt+F2 or Fn+Alt+F2 is the key combination you are looking for.
To open any window just specify the location as shown below in screenshot.
This method is very quick as it gives suggestions also. When I type
Do it give suggestion for
Downloads (see screenshot)
EDIT: Another useful method to quickly excess file and folders
Use super + F
This will show you frequently and recently used files and folders. Just type the few starting words of your file/folder and it will show you that file/folder and then hit enter to open the file/folder.
These two methods will greatly save your time and make you more efficient.