Such as, in many
tales, a sailor may wandering on the sea, then sees a beautiful isle on horizon, with palaces made from gold and silver, and with immortals live on it. It's named Penglai. Some times they can come to its shore, some times they can't reach it. In some tales, there are fruits which can heal the people who eat it and give them eternal youth, and the immortals called the Three Stars are said to live in there, one of happiness and good fortune, one of wealth and high social status, one of healthy and long life. And many others appear. It's said that some emperors in ancient times send out sailors to search for it, to find the elixir of immortality.
Sorry for my not-so-good English! I think it's understandable…maybe.