The Hot Springs in Santorini are one of the best natural springs that you can go to in Greece. They are heated by the islands volcano that is underneath the ocean, causing the springs to be extremely warm and offer a very relaxing experience. There are two small islands near Santorini in which you can be able to access the Hot Springs. You will need to take a boat to Nea Kameni or Palea Kameni. You will notice that the water is slightly yellow, but this is because it has a higher amount of sulphur than regular seawater, so no need to be alarmed. I hope you enjoy the Hot Springs!