The "Caves" of Rapa Nui (Easter Island)

According to a recently published book based on research by several Polish scientists [2], there are more than a thousand caves on Rapa Nui (Easter Island) [3], some 300 of which have been documented in sufficient detail for tourist exploration - as a complement to the moai, the spectacular stone monoliths that are the island’s icons around the world. Some of these, according to the authors, were used as cemeteries and sanctuaries, and some include rock paintings or petroglyphs.

In reality, Rapa Nui has no caves whatsoever, at least in the strictest geological sense - proper caves are created dissolving limestone. According to California archaeologist Georgia Lee, who has decades of experience on the island and has explored most of the “caves” in question, “These are volcanic tubes,” created as underground lava flows cooled, leaving vacant spaces behind them.

On the surface, their openings take the form of grottos such as Ana Te Pahu (pictured here; “ana” is the Rapanui word for the entrances to the tubes). Here, on an island with little topsoil and no surface streams, the natural moisture and soil accumulation make it possible to cultivate sunken gardens known as “manavai,” with traditional Polynesian crops such as bananas and the tuberous taro [4].

Lacking the spectacular stalactities and stalagmites of true limestone caverns, the tubes are unlikely to match the notoriety of the iconic moai, but they are an underappreciated aspect of what, for its size (only 171 square km or about 62 square miles) may be the world’s most interesting island. By jet, it is about five hours west of the Chilean mainland.