Show Hidden Files in Nautilus
The default file browser in Ubuntu is Nautilus.
Any file or folder that has a full stop (‘period’ to our trans-Atlantic cousins) as the first character of its name is considered to be a hidden or system file or folder and they do not show up in Nautilus.
To make hidden files and folders appear in Nautilus, type Ctrl+H
To make Nautilus ignore them again, type Ctrl+H once more.