Sometimes when a project comes to a close, you don't really need to have the project on your account anymore and yet deleting it completely seems so "final".
Luckily, there's an easy way to export your project so that even after everything is done, you can still have a copy of work for your records.
Just click the cog icon in the left-hand column next to the Project name, and choose "export bugs":
Then you'll get a pop-up like the one below. Simply choose the format and what boards you wish to export, and we'll work behind the scenes and then email it to you once it's ready (which usually only takes a couple of minutes):