Winners of the ancient Olympic Games received olive wreaths, not gold medals.
Why it is true
The olive branch was a sacred symbol of peace and victory in ancient Greece. Gold, silver, and bronze medals were only introduced in the modern 1896 games.
Source: History
Would you rather be asked first?
This is the reading side of the site, so the answer is in the sentence above — that is the whole point of it. Test yourself works the other way round: the question comes on its own, and the fact and the explanation only appear once you have answered.