Caves, Cisterns and Therms on the Red Sea Coast: Proof of Greek and Ptolemaic-Roman settlements?

By Michel Pons  Text and photos ©2009 by M. Pons

The First ‘Re-Discovery’
In mid-November 1988, while I was in Nice, France, I received a phone call from my good friend Pascal d’Ursel asking me to join him on his sailboat at Suez for a trip down the Red sea and the Indian Ocean to Kenya. I grabbed a few books and my girlfriend and four days later we were sailing south, admiring under the spinnaker the majestic mountains of the Sinai taking fire at sunset. The 42-foot sailboat had a retractable keel and was equipped with the first SatNav device allowing us to have a precise position every six hours, a must at the time, which gave us the confidence to risk coastal navigation. We were in no rush and decided to stop and visit as many creeks and islands along the African coast as we could.

Red-Sea Cisterns
My literature included the book “Mes Secrets de la Mer Rouge” (My Red-Sea Secrets) by French sailor and adventurer Henry de Montfreid, telling us briefly that in the 1930s on the southern coast of Sudan he went onto an island and bought fresh water that was stored in cisterns carved in the ground.

Ancient Caves and Bathtubs

This was a place to visit! And in fact, when we stepped on this island, what we saw was worth the tricky navigation to get there. It is a whole complex of cisterns, caves, bathtubs, excavations and galleries carved into the limestone rock, containing hundred of cubic meters of fresh water. It immediately brought to mind some Pharaoh of the past and the hundreds of workers needed to achieve this complex. It also told me that the Ancients of this place had a pretty good knowledge of water-management. We spent a few days here taking baths in the cool caves and washing clothes at the cisterns. I took a few photos and did not pay attention to a few ruined houses marked on the charts as “ruins of a fishing village.”

Since then I have been gathering information about the area and realize that the place was unknown to Science.

The Second Approach
In April 2004, with Archaeologists Steven S. Sidebotham and John Seeger, we organized a brief survey in the region and discovered inland, close to this island, Classical looking remains such as pieces of fluted columns, stellae and a necropolis. On the island, Steven thought that the ruined “houses of the fishermen” were Roman and that the harbor with this complex water-cistern facility was certainly linked to the ancient maritime trade route established at Pharaonic and Ptolemaic time.

Greek and Roman Ruins in the Sudan
This was fantastic for me to be first hand with specialists able to recognize the first Greco-Roman remains found in Sudan; but our trip was short, we had to leave and we knew that we were leaving many unknown ruins behind us. We swore to return...

Back home in Brazil I started to search the coastal ruins with satellite imagery and, consulting with the other team members, spotted dozens of ruined sites that appear not to be known to science.

Third Red sea trip in 2007

I decided to continue the search even without any sponsor, spurred on by documentation ranging from the Greek Geographer Strabo to high-tech satellite images. Irresistibly attracted by the ‘new’ ruins spotted from space and matching with the ancient texts, I convinced my good friend Pascal to sail again in a coastal navigation, as the Ancients did, from Egypt to Eritrea.

In May we started to try to systematically survey the harbors that the Ancients might have used. We found several ruined sites along the route, and, near the Northern border of Eritrea came across the most fantastic place that I could ever dream of finding: a harbor at an island where dozens of ruined ‘houses’ and underground cisterns give testimony to past activity.

All constructions are made with cut coral blocs involving a high architectural knowledge. They have been plastered inside with mud that seems to have been ‘baked’ on the spot in order to guarantee that the cisterns would be waterproof. Once again we found underground containers that seem to have been strategically positioned to receive the rain water flowing from probably artificial supports, gathering together hundreds of cubic meters of fresh water.

Ptolemaic Ruins on the Eritrean Coast
We also came upon Classical looking architecture and water-management systems, room for a garrison and good anchorage for ships. These are all the signs of a Ptolemaic settlement. Perhaps this is the harbor found by Ptolemy Philadelphus (Also known as Ptolemy Philadelphia, King of Egypt from 283-246 BC) in about 254 BC: The lost city of Ptolemais Theron (Ptolomais of the Hunts), a marketplace on the African Side of the Red Sea.

Many places remain to be confirmed, dated, and discovered.
The danger to sail inside the reefs is real. The depth on charts is only approximate, and on several occasions we noted close to zero depth below the keel.

Searching for Ptolomaic-Roman settlements

I could not visit all the positions that I wanted to along the African coast of the Red sea, but the first photos of these unknown places that I brought back are gathering the interest of several scientists from France, USA, Great Britain, Italy and Brazil. We now form a complete team looking to go back sailing in the Red sea to scientifically identify and date the occupation of the sites I have visited before, and discover what the coastal ruins, spotted on satellite imagery, exactly are. We expect to confirm the locations of the Ptolemaic-Roman settlements known only through literature, and the two oldest fish-farm complexes from Pharaonic time.

This is only one part of the story. Literature tells us that the first maritime route of the Red sea was a chain of ports ‘on the left hand side, going south’. That is the Arabic coast of the Red sea, and we hope that our project and team will gather interest and help and continue to shed light on the world’s historical and geographical heritage on the coasts and islands of the
Red Sea.

Therm found in 1988. We bathed and washed clothes in this pond which gives access to several bath rooms. It seems that the whole place was once completely underground and collapsed.


Ancient bath tub: note the marks of the tool used to carve the limestone.

The Roman Therms

Much More than Hot Water

Therms (or thermes and thermae) are Roman baths and you can find the ruins of Roman bath houses all over Europe. These baths were heated via a hollow floor called a hypocaust, through which hot air was forced to rooms called the Caldarium and Tepidarium. There was also a Frigidarium featuring a cold plunge-bath.

Roman therms had a social function which we moderns find it difficult to appreciate. First of all, they were frequented by absolutely everyone, even the slaves and the very poor. According to Wikipedia, in the baths you could "exercise, read, drink, shop, socialize and discuss politics. The modern equivalent would be a combination of a library, art gallery, mall, bar/restaurant, gym and spa."

Point of entry for rain water, at ground level, into the underground cistern.


Cave found on a Red Sea island. The water inside is fresh and cool while it’s 35° Celsius outside. The literature says that “Julian, sent by Justinian to Nobatia in about 542 was suffering from the heat and used to take baths during the day in caverns filled with water, undressed, like the natives."

Several entrances to underground cisterns on the same island (see above).

Cave One. This may look like a natural cave, but it's not. See the following picture.

Inside Cave One there is a large room of 10 X 2.4 meters with an opening on the roof, note the square shape of the walls instead of an arch. The walls and roof are plastered with a mixture of clay and coral powder that seems to have been baked on the spot.

Red Sea Therms: Pascal d’Ursel in 1988. Openings give light and ventilation to an underground gallery with bath rooms.

Michel PonsMichel Pons is now organizing a new expedition to the Red Sea. If you are interested, or if you know of a group or individual that might want to support such a project, see The Ptolomies and the Red Sea.


If you would like to contact Michel Pons, his email is redseasurvey @ (Please REMOVE THE SPACES from this address before using).