The remaining two labours only exist because Eurystheus claimed that two of the other labours (the slaying of the Lernean Hydra and the clearing of the Augean Stables) were not fairly completed and were thus discounted. 

The Hesperides were a group of nymphs that were, in some tales, the daughters of Atlas and the protectors of the golden apples of their garden. It took Heracles a mighty journey to reach the garden of these nymphs, where he knew that stealing the apples would be either impossible or increasingly difficult. Noticing Atlas, who was holding the sky aloft, Heracles made him an offer. Knowing that Atlas was the father of the  Hesperides, he asked him to retrieve three of the fabled apples whilst he carried the weight of the sky. Atlas, eager to be free of the burden, agreed and Heracles took the sky upon his shoulders. 

After a short while, the Titan returned with the apples but didn’t want to resume his punishment. Heracles realised that he must resort to trickery and agreed but only wished to be given a momentary relief so that he could fashion a cushion of sorts for his back. The Titan obliged and held the sky, believing that he would be free of the weight just after Heracles made his cushion. The demigod, however, took the apples and wandered off back to Eurystheus.