Student or Learner
They converted the building into a hotel' As the last ditch effort to save it'
here, what does 'last ditch' mean?
Is this a idiom?
Think of military defences: Ditch (fortification) - Wikipedia, the free encyclopedia
(That article seems to talk primarily about ditches in front of castle walls. A cheaper and less permanent option was to use one ditch at he front of your defenive position (but with others behind - so that you you could keep falling back).