What is Ball's Pyramid?
Ball's Pyramid is a dramatic volcanic sea stack rising about 562 metres from the Pacific Ocean, around 20 kilometres southeast of Lord Howe Island. It is the tallest volcanic stack in the world.
The pyramid is the remnant of a shield volcano that formed about seven million years ago. Erosion has left a sharp, jagged spire.
It was first sighted by Europeans in 1788 by Henry Lidgbird Ball, a Royal Navy officer, after whom it is named.
The Lord Howe Island stick insect
Ball's Pyramid became famous in 2001, when scientists discovered a small population of Lord Howe Island stick insects living on a shrub on its slopes. The species had been thought extinct since the 1930s on Lord Howe Island after rats arrived.
A breeding program at Melbourne Zoo has since produced thousands of stick insects, and plans have been made to return them to Lord Howe Island.
Ball's Pyramid is part of the Lord Howe Island Group World Heritage Area. Climbing has been banned since the 1980s. Visitors can see it on boat tours or scenic flights.