Ahu, the ceremonial center of Easter Island

The ahu is the representative ceremonial center of Easter Island. Its platforms stand out, which are of various types, but the most spectacular are the so-called ahu moai, built to display the moai or the giant statues that represent the ancestors.

The marae: origin of the ahu of Easter Island

The religious beliefs and power of the ruling classes in Polynesia, as in many other civilizations in the world, originated the construction of great monumental structures. These architectural ensembles are called marae, a word of Polynesian origin that describes an open and clear space used as a meeting place.

Basically, the marae consisted of a rectangular plaza, sometimes paved and completely walled, and a platform of low, elongated stones at one end. On it, vertical slabs of stone or coral were placed, or wooden figures representing the ancestors or gods.

Notable examples of these megalithic expressions are found throughout Polynesia, in the marae of the Society Islands, the heiau of Hawaii, the me’ae and tohua of the Marquesas Islands, the tu’ahu of New Zealand and, exceptionally, in the ahu of Rapa Nui.

The first ahu of Easter Island were built by the Polynesian settlers who arrived on the island inspired by the basic architecture of the marae and, over time, they acquired their own elements and construction characteristics.

Function and characteristics of the ahu

The ahu was the political, social and religious center of the different tribes and clans of Rapa Nui. Here any important gathering took place: ceremonies, funeral rites, assemblies, initiations, and parties to celebrate the harvests and distribute food.

The ahu were sacred places dedicated to ancestor worship. Each lineage had its ceremonial center in a sector near the coast, from which it controlled a part of the territory towards the interior of the island.

The word ahu designates the entire monumental ensemble but is used, more specifically, to refer to its main element: the altar or ceremonial platform on which one or more moai statues were placed, representing the ancestors of each family group.

Read more about Moai, the giant statues of Easter Island

The statues were part of a symbolic system that gave the ancestors a supernatural power called mana. This power, embodied in the authority of the ruling class, protected the community and provided abundant fishing and harvesting.

The first platforms of the island were simple and small altars without statues or perhaps with wooden figures as in other Polynesian islands. Later it seems that they included red slag figures with naturalistic features, possible precursors of the moai. The oldest of the structures is believed to be the first phase of the Ahu Tahai dating from the 7th century.

The ahu evolved over time and grew in size and complexity. An inclined plane in the front (tahua) paved with round stones (poro), and other constructive and aesthetic elements such as lateral wings, crematoriums and larger and more stylized statues were incorporated into the central platform.

The stage of megalithic expansion on the island must have started towards the end of the first millennium of our era. The last ahu were being built around the 17th century, which means that in a relatively short period, about 500 years, the Rapanui people managed to build about 300 ahu and around 1,000 moai.

The vast majority of the ahu are located along the coast, oriented parallel to the shoreline. However, the position of some are governed by astronomical observations. The platforms form an almost continuous line around the coast, since on average there is less than a kilometer of separation between them. Sometimes, there are several ahu grouped together, taking advantage of especially favorable areas for settlement, near bays or suitable places for landing.

Ahu Moai

Different types of ceremonial structures have been found in Rapa Nui, but the most prominent and abundant is the so-called ahu moai. This type of ahu, named after incorporating the moai statues on its platform, constitutes the most characteristic construction of classical Easter Island architecture. Next we will explain the main elements that compose it.

The central platform, the main element of the structure, stood parallel to the coast and as close as possible to the sea. It was made up of a core of earth, stones, and debris covered by large slabs fitted together. At the top rested the moai, the images representing the ancestors, whose heads used to be covered by the pukao, some headdresses of red scoria.

More information about Pukao, the headdresses of the moai statues

In the phase of greatest apogee, an extraordinary technical mastery was reached, as seen in the perfection of the adjustment and polishing of the blocks of the Ahu Vinapu and the Ahu Te Peu or in the construction of walls capable of supporting increasingly larger and more stylized moai.

Over time, many platforms underwent extensions and modifications to increase their size or improve their appearance. Sometimes, some were deliberately destroyed by rival clans that reused the materials to build a new altar.

Platform modifications often incorporated recycled moai bodies or heads from earlier stages, such as the Ahu Nau Nau at Anakena beach, and pieces of ancient foundations of boat-houses or hare paenga .

In several ahu moai, the ends of the platform were extended with lower structures or small ramps forming lateral wings. At the Ahu Tongariki, the largest structure in Rapa Nui, the central platform, where 15 colossal moai were installed, measured 45 meters in length, and the lateral extensions increased its length to a total of 150 meters.

In front of the central platform and attached to it, was the tahua, an inclined ramp, paved with boulders of marine origin called poro. This ramp ended in an esplanade that served as a large public square where the community gathered to celebrate all kinds of events and ceremonies. In some cases, in the plaza area there were stone circles, called paina, where certain rituals were performed. It is still possible to see these circles in places like Vaihu or Tahai.

Generally, ahu were not designed to contain graves of members of each clan, since cremation was the common custom. In fact, on many platforms crematoriums and burial cists have been found next to the rear wall facing the sea.

Burial chambers or avanga were late additions that were built under the sloping platform or even under fallen moai. This fundamental change in the mortuary pattern was the adaptation to the lack of fuel for cremations. This continued until historical times, as each family recognized their belonging to a territory.

Some ahu, located near small coves, showed stone-paved ramps where fishermen glided canoes out to sea. The most accessible example of this type of ramp can be seen in Tahai, where it is still used today to access the shore.

Finally, in the interior of the area were located the hare paenga or boat-houses, some constructions in the shape of an inverted boat where the chiefs and priests resided. The rest of the inhabitants of the village lived somewhat further away in huts or caves fitted out as permanent housing.

Other types of ahu

Towards the 17th century, a new stage begins, known as the huri moai, where wars between clans take place and ends with the demolition of the statues. The ahu were partly destroyed or modified and under the platforms they built collective graves or avanga. Some were covered with stones to create burial mounds whose shape is reminiscent of a half-pyramid, which is why they have been called semi-pyramidal ahu.

A rarer type of ahu (barely a dozen) and located on the north coast is the so-called Ahu Poe Poe. Named for its small boat shape (poe poe en rapanui), it is made up of an elongated rectangular structure with pointed and raised ends, as if they were the bow and stern of a boat. They normally have a burial chamber along the structure, connected to the ceiling through a series of openings. A variant of this type of ahu is wedge-shaped and oriented perpendicular to the coast.

The influence of astronomy

According to modern astronomical studies, about 20 ahu were intentionally oriented with an astronomical sense, so that the moai would watch the sunrise or sunset at solstices or equinoxes.

In general, the astronomically oriented altars in the interior of the island are associated with the solstices, especially winter ones, while the coastal astronomical platforms are preferably oriented in an equinoctial direction, north-south, so that the moai looked exactly east or west. It may be that those on the coast were related to the location of precise positions from the sea, while inland they had an agricultural sense, especially on the winter solstice.

Among the altars raised in the interior of the island, about 30, there are two notable examples: the Ahu Huri A Urenga, oriented to the sunrise behind the Poike on the winter solstice, the shortest day of the year in the southern hemisphere , towards June 21; and the Ahu Akivi, where the axis of the platform was oriented from north to south, being perfectly perpendicular to the movement of the sun on the autumn and spring equinoxes.

In Vinapu, the Ahu Tahiri marks the equinoxes, and the Ahu Vinapu 2, the summer solstice. The Ahu Ra’ai and Ahu Tongariki is oriented towards the summer solstice.

An open-air museum

The lone figure of the Ahu Ature Huki, located in Anakena, was the first moai to be erected on the island in modern times during Thor Heyerdahl’s Norwegian expedition of 1956. In that group was the North American anthropologist William Mulloy, who returned to Rapa Nui in 1960 to restore the Ahu Akivi together with the Chilean archaeologist Gonzalo Figueroa.

The restoration of Ahu Akivi is considered a turning point in the recent history of Rapa Nui. From that moment on, other works to restore more platforms began. The Ahu Akivi was followed by the altars of Hanga Kio’e, Tahai, Anakena and Tongariki among others. The ancient platforms regained their former splendor and the small and remote Easter Island attracted the attention of other researchers and travelers. Mulloy’s idea of turning the island into an open-air museum came true, and it also sparked a true cultural renaissance, economic development, and a renewed sense of pride in being a Rapanui.

Below we select a list of the main restored ahu of Rapa Nui. We also propose to visit the most interesting platforms that still retain their original state, since it allows you to get an idea of how they were when they were demolished.

The main restored ahu

The main ahu not restored

Location map

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