As a result of a number of "purifications" executed by the city-state of Athens, the entire contents of all Delos Island’s graves (bones and funerary offerings) were transferred to the neighboring Rhenia Island in a common grave called "Vothros Katharsis" (The Purification Pit).

According to an old reference, in 523 BC the Tyrant of Samos Island, Polikratis, had devoted Rhenia Island to Apollo by tying it to Delos Island with a big iron chain. Rhenia, called alternatively “Great or Big Delos”, is four times the size of its sister Delos Island and separated from it by a small strait.

From 426/425 until 1 BC, Rhenia Island was used as a cemetery of Delos Island.

During the Roman period in the 2nd and 3rd centuries BC, Delos was a thriving commercial port exceeding the previous religious importance. The prosperity of Delos declined in 88 BC, following the attack by Mithridates of Pontus, a monarch from Asia Minor and a staunch enemy of Rome, killing almost 20.000 inhabitants and looting the sanctuary treasures. The Romans partially rebuilt the city, but revival was prevented by continuous pirate raids in 69 BC. In the following centuries Delos was gradually abandoned and Rhenia also was forgotten. In 1872 the French Archaeological School of Athens started excavations which revealed the wealth of the island’s history to the entire world.
After the Greek independence in 1830, Delos and Rhenia Islands were designated as areas of great archeological value and by Greek law owning is forbidden since then. However, the habitants of Mykonos can rent in Rhenia some fields for cultivation and farm a few animals (sheep and goats), and pay for that to their municipality.

The “Purification Pit” in Rhenia was discovered and excavated by the Greek archaeologist Dimitris Stavropoulos between 1898 and 1900 covering a surface of 400 m2 and containing hundreds of vessels and funerary offerings made of metal, ivory, marble or glass, graves and cinerary urns of dead people‘s burned bodies. All these findings are exhibited in the archaeological museum of Mykonos which was built for this purpose in 1900.

Rhenia is an uninhabited island with no plumbing and electricity. You come across sheep, the farmers’ cells as well as their stables and fields that are cultivated. Walking up the hill of Rhenia, you can see Delos and Mykonos. On the Island of Rhenia, you can find solitary beaches with exotic coast, with blond sand and clear water. All the beaches are not crowdy at all and no tourism has disturbed its natural beauty. Some beaches to name are Agia Triada, Ligia, Skinos, Nataliotis, Stena, Glifada, Ambelia and all are accessible only by boat.

Very few tourists know about the island or have an interest in going there on a day’s excursion, so if you plan it, it is possible to be the only person on one of its pristine sandy beaches.