The Ancient Greeks are famous for their myths relating to gods and the semi-gods called heroes.
Herakles (known as Hercules by the Romans) was a favourite for myths. That is because he was a strong, fearless kind of chap. So the myths always set him impossible tasks. That was to keep the audience interested.
The most famous of these myths is called the twelve labours of Hercules.
This is what he was ordered to do:
Slay the Nemean Lion.
Slay the nine-headed Lernaean Hydra.
Capture the Golden Hind (deer) of Artemis.
Capture the Erymanthian Boar.
Clean the Augean stables (which were vast) in a single day.
Slay the Stymphalian Birds.
Capture the Cretan Bull.
Steal the Mares (female horses) of Diomedes.
Get the belt of Hippolyta, Queen of the Amazons (who were famous for being strong).
Get the cattle of the monster Geryon.
Steal the apples of the Hesperides
Capture and bring back Cerberus (the three-headed dog).
Another famous myth involved the Trojan Horse. The video below tells you this story.