Ball's Pyramid is an erosional remnant of a shield volcano and caldera lying 20 kilometres southeast of Lord Howe Island in the Pacific Ocean. It is 562 metres high, while measuring 1,100 metres in length and only 300 metres 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 northeast of Sydney, New South Wales.
Steep, 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 difficult.
Wikipedia https://en.wikipedia.org/wiki/Ball's_Pyramid
Coordinates -31°45'13.537" N 159°15'0.644" E