Recover accidentally closed Opera window and its tabs after restarting

I accidentally closed an instance of Opera with multiple tabs. There was another window with a couple of tabs running.

I have closed and restarted Opera in the hope it will retrieve the windows at startup (it usually asks if I want to continue from last time).

Is there a way I can retrieve my closed window with all the tabs? I cannot see them in the history either, probably because when I switched on my PC the Internet connection was down and the pages didn't load.