Atlas is holding up the sky, not the Earth
Look closely at the most famous ancient statue of ATLAS and the ball on his shoulders is covered in constellations. In the Greek story he was never holding up the Earth. ATLAS was a Titan, one of the older generation of gods who fought ZEUS and the Olympians for ten years and lost, and his punishment was to stand at the edge of the world keeping the sky from crashing down on it — forever.
That statue, the Farnese Atlas, a Roman marble copy now in Naples, carries the oldest surviving picture of the Greek constellations on its globe. Somewhere along the way the sky became the Earth in most people's minds, and books of maps became atlases. The mapmaker Gerardus Mercator, who first used the word that way in 1595, insisted he meant a wise old king called Atlas, not the Titan. Nobody listened: the giant bent under a globe went on the covers anyway.
A religion with temples, not a book of fairy tales
For well over a thousand years these gods were worshipped, not just told about. Greeks prayed to them, left offerings of food, wine and animals, and built them homes. The Parthenon in Athens was a temple to ATHENA, and inside it stood a statue of her roughly twelve metres tall, dressed in gold and ivory. Only descriptions and small copies survive.
People travelled to Delphi to put questions to APOLLO, where a priestess called the Pythia gave his answers — often worded so they could be read two ways, which made the god very hard to prove wrong. There was no single holy book, and towns told the stories differently. Even the two oldest poets disagree about where APHRODITE came from: Homer makes her a daughter of ZEUS, while Hesiod has her rising out of sea foam.
Olympus is a real mountain
OLYMPUS is the highest mountain in Greece, 2,917 metres at its tallest peak, and its cloud-wrapped summit makes a hidden palace easy to imagine. The first recorded climb to the top took place in 1913. The climbers found rock, wind and a very good view. HESTIA, goddess of the hearth and the one Olympian supposed never to leave home, was not in.
The twelve Olympians were never a fixed list either. HESTIA appears in some counts and DIONYSUS in others — on the carved frieze of the Parthenon, the seated gods include DIONYSUS and leave her out. HADES rarely makes the twelve at all; he lived below ground and seldom came up.
The hero Hera couldn't stand
HERCULES is the Roman spelling. The Greeks called him Heracles, usually translated as 'glory of Hera' — an odd name for someone that goddess spent his whole life trying to destroy. He was a son of ZEUS by a mortal woman, and HERA took it personally. She sent two snakes into his cradle, and the baby strangled them. Later she drove him mad, and the twelve labours were his penance.
Several monsters in this grid belong to hero stories. Killing the HYDRA was his second labour, and it grew two heads for every one he cut off. MEDUSA was beheaded by a different hero, Perseus, and PEGASUS sprang from her neck. The creatures get a fuller treatment in our mythical creatures puzzle, and the same gods appear under their Latin names in Roman mythology.