but in the silmarillion tirion was deserted because it was 'a time of festival , and wellnigh all the elvenfolk were gone to valimar , or were gathered in the halls of manwe upon taniquetil ' ; here on the other hand it seems at least strongly implied , in both b and c , that kor was empty because the elves of valinor had departed into the great lands , as a result of the tidings brought by the birds of gondolin .