Once upon a time, Theseus along with his friends was returning to Athens, after participating in the Calydonian boar hunt. The river Achelous was swollen with heavy rains, and delayed his journey. The god of the river, also known as Achelous, invited Theseus to safely rest in his home, until the swollen waters subsided to remain within its banks. Theseus gladly agreed and he entered Achelous’ home. It had walls of permeable pumice and stone, the floor was damp with bouncy moss, and the arching roof was made of rows of murex and shells.
Achelous hospitably treated Theseus and his friends, who lay reclined on comfortable couches. Nimble nymphs served a magnificent banquet. Then the nymphs served delicious wine in bowls embossed with precious stones. After enjoying the delectable feast, Theseus pointed his finger at a distant island, enquired its name and wondered, whether it was one island or more than one. Achelous replied that it was not a single island, but they were actually five islands, which due the distance, resembled deceptively as one. And to the further amazement of his guests, Achelous recounted that previously they were five Naiads.
To satisfy the aroused curiosity of his heroic guests, Achelous related the story of the five islands. He told them that long ago, the five Naiads had performed a sacrifice by slaying ten bullocks. They invited all the gods to attend the sacrifice, but they did not invite him. Thus slighted, he became furious and the river swelled with rage. The waters swelled so much that a flood was unleashed. Redoubled with rage and flood, he thrashed all the woods and fields, until the very soil was thrown in the sea, along with the five Naiads. Then, they remembered their neglect of not inviting him, and they sorrowfully regretted their action. The waters of the Achelous river sliced the one solid soil, into five parts and created five islands, which since then were known as the Echinades.
Excerpt from the book “Once Upon A Time-II: 150 Greek Mythology Stories” by Rajen Jani