Off the eastern shore of Pohnpei, in the Federated States of Micronesia, a city of black basalt rises out of a shallow lagoon. Its walls are built from long, crystal-shaped stone columns stacked like logs, and its streets are canals. This is Nan Madol, one of the most remarkable archaeological sites in the Pacific.
For Pohnpeians, Nan Madol is not a mystery to be solved but a place of deep history, chiefly power and story. In this guide we explain what Nan Madol is, who built it, how it was used, and why it matters to Pohnpei and to Micronesians everywhere.
What is Nan Madol?
Nan Madol is a ruined ceremonial and political centre built on artificial islets in a lagoon off Pohnpei’s eastern coast. Constructed from basalt columns and coral fill, it was the seat of the Saudeleur dynasty, which ruled Pohnpei for several centuries. It became a UNESCO World Heritage Site in 2016.
Where is Nan Madol and what does the name mean?
Nan Madol lies in the Madolenihmw district of Pohnpei State, between the main island of Pohnpei and the small island of Temwen. The name is usually translated as “within the intervals” or “spaces between”, a reference to the network of tidal canals that run between the islets.
The core of the site covers an area of roughly 1.5 by 0.5 kilometres and contains close to a hundred artificial islets. Sources give slightly different counts: Wikipedia lists 92 islets, the US National Park Service says over 90, and UNESCO describes more than 100. Each islet is a platform of stone and coral fill surrounded by water.
Who built Nan Madol, and when?
Nan Madol was built by the ancestors of today’s Pohnpeians. Radiocarbon dating places the start of megalithic construction around AD 1180, and UNESCO dates the main building period to between about 1200 and 1500 CE.
The Saudeleur dynasty
The site was the ceremonial and political seat of the Saudeleur, a line of rulers who united Pohnpei under a single, centralised authority. According to the National Park Service, the Saudeleur first appeared around 1100 and built Nan Madol from around 1200. Their rule lasted roughly 500 years.
The legend of Olisihpa and Olosohpa
Pohnpeian oral history tells of twin sorcerers, Olisihpa and Olosohpa, who arrived by canoe looking for a place to build an altar to the god of agriculture. After several attempts they chose the reef off Temwen. In the legend, they used magic, helped by a flying dragon, to lift the great stones into place. When Olisihpa died, Olosohpa became the first Saudeleur.
Isokelekel and the end of the Saudeleur
The Saudeleur era ended when the warrior hero Isokelekel led an invasion, around 1628 according to archaeologists. Oral history describes him as a demigod, son of the storm god Nahn Sapwe, and historians believe he and his followers came from Kosrae. His victory began the Nahnmwarki era, the system of paramount chiefs that is still part of Pohnpeian society. Isokelekel lived at Nan Madol, but his successors later abandoned it.
How was Nan Madol built?
Much about the construction is still unknown, which is part of what makes the site so striking. Here is what researchers do know:
- Basalt columns: the walls are made of naturally formed, prism-shaped basalt, quarried elsewhere on Pohnpei and brought to the lagoon.
- Header-and-stretcher stacking: the columns are laid in a crisscross pattern, alternating directions, with no mortar or binding agent.
- Coral foundations: the islets sit on a coral reef base just below the water’s surface, filled with coral rubble.
- Huge stones: some stones are small enough for one person to carry, while the heaviest pillars are estimated by the National Park Service at around 100,000 pounds.
Exactly how such heavy stones were moved across the island and into the lagoon has not been proven. Researchers have suggested various methods, but the honest answer is that nobody knows for certain.
What was Nan Madol used for?
Nan Madol was not an ordinary town. It was divided into two broad areas: a mortuary sector, Madol Powe, in the north-east, and an administrative sector where the rulers lived and worked. UNESCO lists stone palaces, temples, tombs and residential areas among its structures.
Nandauwas, the royal tomb
The largest and best-known structure is Nandauwas, the royal mortuary islet. Its walls rise to around 5.5 to 7.5 metres and surround a central tomb enclosure built for the first Saudeleur.
A city of priests and specialists
Many islets in Madol Powe were home to priests. Others had specialised uses, such as food preparation, canoe building and coconut oil production. Because the Saudeleur concentrated power at Nan Madol, food and goods had to be brought in from the main island, a sign of how much authority the rulers held.
Why is Nan Madol important today?
Nan Madol was listed as a US National Historic Landmark in 1985 and inscribed as a UNESCO World Heritage Site in 2016 under the name “Nan Madol: Ceremonial Centre of Eastern Micronesia”. At the same time it was placed on the List of World Heritage in Danger. UNESCO identifies siltation of the waterways as the main threat, because it allows mangroves to grow unchecked and undermine the walls.
For Pohnpeians, the site is a living link to chiefly history and to the stories that still shape identity on the island. It sits alongside other expressions of culture, from traditional titles and feasts to dress such as the Pohnpeian skirt. If you are interested in that side of island heritage, read our guide to the Pohnpeian skirt (urohs) and our overview of Micronesian traditional attire.
Can you visit Nan Madol?
Yes. According to the National Park Service, Nan Madol sits on land owned by Pohnpeians but is open to the public, and boat tours of the canals are available. Practical tips for a respectful visit:
- Check access and tour arrangements in advance with the Pohnpei Visitors Bureau or the FSM Visitors Board.
- Dress modestly, covering the thighs and shoulders.
- Treat the site as sacred: do not climb on walls or move stones.
Key takeaways
- Nan Madol is a basalt city built on artificial islets off Pohnpei’s eastern coast.
- It was the seat of the Saudeleur dynasty, which ended around 1628 with Isokelekel’s arrival.
- Construction began around AD 1180; how the heaviest stones were moved is still unknown.
- It has been a UNESCO World Heritage Site, and on the In Danger list, since 2016.
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Frequently Asked Questions
Who built Nan Madol?
Nan Madol was built by the ancestors of the Pohnpeian people under the Saudeleur dynasty, starting around AD 1180. Pohnpeian legend credits the twin sorcerers Olisihpa and Olosohpa.
How old is Nan Madol?
Megalithic construction began around AD 1180, and UNESCO dates the main building period to about 1200 to 1500 CE, making it roughly 800 years old.
Why is Nan Madol called the Venice of the Pacific?
Because it is built on artificial islets separated by tidal canals, much like Venice is built on islands linked by waterways.
Is Nan Madol a UNESCO World Heritage Site?
Yes. It was inscribed in 2016 and placed at the same time on the List of World Heritage in Danger, mainly because silt and mangroves threaten the structures.
Can tourists visit Nan Madol?
Yes. The site is privately owned by Pohnpeians but open to the public, and boat tours through the canals are available. Check arrangements locally before you go.
