Over the years a few of the hostels I have stayed at on my hikes have closed, whether due to changing times or changing hiker attitudes, it seems like a lot of good places are gone.
A few that come to mind:
Rainbow Springs campground
Graymoor Monastery (actually staying in the rooms)
Manchester Center church hostel
Dartmouth - Stayed at the Foley House a few times. Seems like student housing options are now off-limits to hikers
What other hostels do you remember staying at that are now history?