However, there's another set of pics which I did import to Lr which now look greyish when viewed. I think this means they have been imported but I can't seem to access them!
Are you talking about photos looking grayish in the Import dialog box? Or somewhere else?
Yes it is when I am trying to import photos. I thought that I had already imported these pics so any idea why they are not in the Annecy folder?
We need to be careful about the phrasing here. Folders and collections are not the same thing.
Folders are where your images are located on your hard drive. The images exist only in one folder.
Collections are groups of references to your images. An image can be referenced by zero, one, or many collections.
For the grayed images in the import dialog, note some of their names.
Exit the import dialog, go to the Library grid.
Click on "all photos" on the left. On the top of the screen, search for one of the file names.
Right-click on the found image, select "show in Folders". This will tell you where LR thinks the image already is.
If you really did import them previously, and they are not in the expected folder, it is most likely because you (accidentally) imported the photos into Lightroom instructing Lightroom to copy or move the photos to some other folder. Please follow the instructions by ManiacJoe to find the photos in Lightroom. Once found, you can move the photos to the desired folder.