This pretty tittle palace is the Temple of Asclepius on the Isola Tiberina (Tiber Island) in Rome. It is not the only Temple of Asclepius, though it is the only one in Rome …
Naturally, it would never do to have just one Temple of Asclepius (or one ‘Asclepeion’, as posh people say) in the ancient world any more than it would do to have just one hospital in a modern-day state — because Asclepius (or ‘Esculapius’, as the Romans called him) was the Greek god of medicine, and his temple was a place of healing, where those who were feeling a bit poorly would go to be cured.
We can readily assume (without wishing to offend anyone who still believes in the existence and power of the god Asclepius) that those who arrived with serious illnesses did not recover. Yet we can also assume, because there were many temples of Asclepius in the ancient world, and people did visit them, that lots of people did find that they felt just an ickle bit better after spending some time resting up at an edifice such as this one.
It may have been simply that the combination of good food, clean water and a bit of time off work perked them up. (Or, of course, it may have been because the place is magic!) It’s not so strange. We know that people used to go to Stonehenge for similar reasons, and that they still do go to Lourdes, and other places, and that sometimes healing does occur. Maybe that’s why spa holidays are so popular these days.