Large folders that have been deleted and are not showing in the recycle bin

If it was too large for the recycle bin then the delete function simply bypassed the bin and permanently deleted it. You won't find it anywhere in that case. Hope you had a backup.

First, do not write ANY data to the drive then try to get back what you can with something like Recuva

http://www.piriform.com/recuva

Only recover to another drive/network location/flash stuck/ect

Files are not deleted from a hard drive, but simply marked as FREE space. so as long as they do not get overwritten, you can get them back.

Its a bit harder on SSD's, but many times you can recover on those as well.

Newer SSD's do a form of garbage collection almost immediately upon a deletion, making recovery virtually impossible. I'm seeing this more frequently in my forensic work as SSD's become more mainstream.

^ As nukemaster said that would be your best bet. But if you have already written to the drive it may be to late.

Your can also right-click your trash can and select properties. From there you can increase the size of the trash bin if needed. Of course this will only take effect for future deletions.