Ball’s Pyramid is an erosional remnant of a shield volcano and caldera lying 20 kilometres (12 mi) southeast of Lord Howe Island in the Pacific Ocean. It is 562 metres (1,844 ft) high, while measuring only 1,100 metres (3,600 ft) in length and 300 metres (980 ft) across, making it the tallest volcanic stack in the world. Ball’s Pyramid is part of the Lord Howe Island Marine Park in Australia and is over 643 kilometres (400 mi) northeast of Sydney, New South Wales.
Steep and eroded, and formed 6.4 million years ago, Ball’s Pyramid is positioned in the centre of a submarine shelf and is surrounded by rough seas, making any approach a difficult one.
Source: Ball’s Pyramid – Wikipedia