Mangaia is the most southerly of the Cook Islands, and the second largest, after Rarotonga.
Geologists say the island is 18 million years old, the oldest in the Pacific.
It rises 4750m above the sea floor, with a land area of 52km2.
It has a volcanic plateau and is surrounded by a ring of fossilised coral cliffs around 60m high, called makatea.
The highest point is Rangi-motia, at 169m. The freshwater Lake Tiriara is in the south.
The population of Mangaia is 700 people.
The capital is Oneroa village, on the west coast, with half the population.
There are two more villages, Tamarua in the south and Ivirua in the northeast.
Mangaia is renowned for its shell neckbands or “eis”.
These are made from a tiny yellow snail which emerges only after rain.
The women give these away as prized gifts of friendship to visitors from other islands.
Mangaia is renowned for coconuts, an important crop even today, providing food, coconut milk, and fibre.
Before settlement by missionaries, Mangaia was ruled by warriors who fought over land and crops.
The first recorded European to arrive at Mangaia was Captain James Cook, on March 29, 1777.
Long ago, during a trip to London, Numangatini, or “King” John of Mangaia, received from Queen Victoria a Union Jack flag.
Mangaia is a good destination for those who want to relax and experience slightly cooler temperatures than on the other Cook Islands.