Henderson, a 31-square-km elevated atoll 169 km east-northeast of Pitcairn, is the largest of the Pitcairn Islands. The island measures 5 km by 10 km and is flanked by 15-meter-high coral cliffs on the west, south, and east sides.
Geologists believe that Henderson was uplifted after a volcanic eruption on Pitcairn over a million years ago which tilted the earth's crust slightly with its weight.
Henderson is surrounded by a fringing reef with only two narrow passages: one on the north, the other on the northwest coast. The passages lead to a lovely sandy beach on the island's north shore. Plenty of shade trees are there.
The interior of the island is a flat coral plateau about 33 meters high, but the dense undergrowth, prickly vines, and sharp coral rock make it almost impenetrable. There's said to be a freshwater spring visible only at low tide at the north end of the island, but this is doubtful, and no other source of water on the island is known.
There are four endemic species of land birds on the island: a black flightless rail (Henderson chicken), a green fruit dove, the Henderson lorikeet, and the Henderson warbler. Great numbers of seabirds nest here. Fish and lobster are also numerous, as are Polynesian rats. The Pitcairners visit Henderson to collect miro wood, which is excellent for carving.
Sometime between 1200 and 1500 AD Henderson was inhabited by Polynesians who died out or sailed away prior to the arrival of Europeans.
Discovered by Europeans in 1818, it was first visited by the Pitcairners in 1851. There was talk of constructing an emergency runway on Henderson to support air services between South America and the South Pacific but this was rejected, and in 1988 the island was declared a World Heritage Site, the first South Pacific locale to be added to UNESCO's prestigious list.